I know you don't care about most of this (and I'm not saying you should care about most of this, and I've already said my piece on how I'd recommend moving forward...), but the specifics aren't the point of this. The point of the systematic nature of the electrical code.
I do believe it would jeopardize safety of the device but not of house.
Using the ground wire as a a current path will affect EVERY ground wire in the installation, and the devices attached to them. If that doesn't make sense, and no offense is intended here, then you've either missed something in your understanding of electrical potential and current flow, OR, you've not considered the whole circuit. Even though you can see the "bond", ALL of the wires in your entire electrical installation, the hots, neutrals, and grounds, each and every one of them are eventually connected to each other at both ends.
...Inside my electrical box the ground and neutral are bonded...
...(in this case it’s an outbuilding with its own panel)...
Which electrical box? For the house, your neutrals and grounds need to be bonded ONE TIME, at the "service equipment". That's the main feed from the power company, and it's done at the first shutoff after the meter, and some specified maximum distance from the meter. That could be your "main panel", in which the panel enclosure would be where the bonding takes place or that could be a dedicated shutoff prior to your main panel. In that case, the shutoff would be bonded, and the "main panel" would not be bonded.
I'm not taking that on, as I can only assume that the separate building was done correctly. That's not something that one can realistically take on in a text based, remote discussion.
Outbuildings have some different rules. Depending on several factors, you either carry the ground AND the neutral to the outbuilding, and utilize them there (which makes the outbuilding no different than an extra bedroom within the house, everything is still connected). In that case the outbuilding's panel is NOT bonded. Or in other circumstances you'd feed the outbuilding with two hots and a neutral, omitting the ground, and the ground is reestablished at the outbuilding, and there is again ONE point that the outbuilding is bonded. That will be at the first disconnect after the entrance to the outbuilding. Those are two very different scenarios, with criteria that dictates which way it needs to be. Sometimes those decision scenerios are as simple as if you did or did not run the forth wire, other times it's more involved. But depending on the variables that set that decision in stone, either way, the wiring will be wired, and function exactly how you'd expect it to, and it will work as it should. UNTIL you start doing non-standard things. Then, honestly, all the internet advice is a shot from the hip.
If you have the ground reestablished (not carried) to the outbuilding, you can omit the house wiring from being a part of the equation for THIS question. (Other questions will still affect the house as well). If you have four wires physically run out to the separate building, the building, I'm not aware of any exceptions, I think it's already set that you can't re-establish a ground at the building, and that panel must not be bonded.
In either situation, stealing a curent path from the ground wire MAY cause something else, somewhere else to have voltage available where it shouldn't be.
This is one of the many things that the codes do for you, EVEN IF you live where there are no codes whatsoever and nobody cares... It makes a system, such that what you did sixty years ago, what you do sixty years from now, what you did yesterday, and what you do tomorrow, they'll ALL work transparently with each other. That was the basis for my suggestion above. Re-identifying the wire on the lathe's whip, making it neutral instead of ground, That's how dual voltage appliances were always done. And the fact that "cheating" will work fine in some cases... It affects things in the future. Doing the lathe "to code" even though that "three wire" code is obsolete, plus it isn't required to do so, means that even though grounding through the neutral is obsolete, the code (and non-code wiring that is done to code) will recognize it, and it will not have adverse effects (beyond an outdated appliance that isn't up to modern UL and other codes). It doesn't maintain the integrity of one circuit, it maintains the integrity of the whole entire electrical installation.
What about this idea? Say thr outlet is properly marked that it is 220v. This example actually takes place in real life. There are 12v bulbs that have the same base as their 110v counter parts. Does this seem like an okay situation? I will end up not stealing a ground so that will be intact and the light will be 220v. Assuming I can find a light, I feel like led bulbs might go up that high.
That's an awesome example of "keeping things right". These bulbs are way outside of electrical code, but it's the same thing. The NEC ended at the box upon which you screwed a bulb base. Or at the outlet where you plugged in the lamp. Those fall under a listing agency. UL, CE, etc. but t you can be assured that they all know about each other. If you screwed a 12 volt light bulb into a 120 or 240 volt outlet, one of two things is going to happen. Either the resistance is too low, so it draws way too much current, and the breaker trips, OR, the filament is unable to handle the current that's way above it's rating, and the filament melts, inside of it's enclosure, untouchable by you, and opens the circuit, eliminating the fault. That's why light bulb bases are so universal compared to other things, the bulbs can't catch fire, smolder, carry on, or stand generating any level of heat that wasn't designed in. They can act as their own fuse, and the overall design of the product is intrinsically safe, even if you screw up. Their design also negates the need for a ground wire at the bulb, even though the box that the light is plugged into still needs that ground wire. You still see such devices today, which still to this day, come without the third pin on the plug. NEC says the ground pin must be available and wired in on the receptacle, but that's where they end. The two prong appliances (and light bulbs) fall under a different system, designed to work with NEC compliant power, but the fault protection level that the ground wire would have provided, that's built in.
In contrast, a counterpoint is that the outlet that the lamp is plugged into... You don't have the same degree of universalness. Each voltage and each circuit breaker size small enough that it's plausible to use a plug connection for, each breaker size has it's own dedicated plug, that does not interchange with any other. That seemingly arbitrary wagon load of different plugs is necessary so that you can't plug ten amp things into 50 amp circuits. The device would work, and it would control it's own current draw, so long as it was in working order and all was right in the world. In a fault scenario though, it's not capable of SAFELY restraining that much power, such as the larger breaker is cable of delivering. And so it spirals into confusion with more outlets/plugs than you can shake a stick at. But they solve a real world problem. They keep both circuits AND appliances from becoming a problem.
That being said, the side of me talking myself out of it is going to come out. I “think” the unsafe scenario there would be the same reason a travelers or Chicago 3 way is illegal. Since the appliance has a single pole switch when hooked to 220v it would still have 110 voltage potential in the socket from the other leg right?
I'm not sure I understand your analysis there, but yes, the "Chicago 3 way" is a perfect example. It's a very one dimensional analogy to this ground vs neutral thing. Let me make another analogy- The Chicago 3 way issue is a very two dimensional issue which fits very beautifully on a sheet of paper, and the danger is very specific, targeted, pinpointed, and quite clear. The ground/neutral question, that's a four, arguably five dimensional issue that makes a VERY complicated drawing of multiple, simultaneous current paths and fault modes and design decisions and permutations and variables based things about the entire electrical system that were probably never written, and were no longer available after the original electrican went on to the next job. But it's the same thing. It's a perfectly good way to make the light work. It's not intrinsically unsafe, EXCEPT.... It didn't fit "the system". Unless you've used conduit as a ground circuit or something like that, where continuous current is an issue, the available issues are all very unlikely, but when you add them up, coming from every possible direction, the whole risk becomes beyond tangible to kinda real world. Had the three way circuit been a thing at the time light bulb bases were standardized, the bases would have been done (slightly) differently, and that simple Chicago 3 way circuit would have had ZERO problems. Zero. Due to the simplicity of it's installation and typically lower wiriing cost, I suspect it would have been our defacto standard. The problem is, that to standardize that would "break" too much of the rest of the system. So the Chicago 3 way circuit was rightfully outlawed, not for being dangerous, but because it is not compatible with the rest of the established system.
Trivia- It wasn't specifically outlawed. It was fine in the knob and tube days, and probably the least of anybody's worries. Time's moved on though, and the hot socket isn't allowed any more.
Before polarized and grounded plugs was there just a chance you would get zappec when changing a bulb if you made a path to ground and touched the screw base? (In this scenario the lights plug was installed into the outlet with the bulb screw base circuit on the black wire or load side)
That was real. But just like plugging the lamp in in the first place, you learned right quick to keep your fingers off of the metal parts. Most people today never had to learn to be careful of a light bulb. Forget getting electrocuted, you don't even have to grab a paper towel to unscrew a dead one because they don't get hot anymore..... But the code still recognizes those old appliances, old bulbs, and our electrical outlet situation is still designed, to this day, to accept, accommodate, and protect those old appliances just as well as they ever were, and ever could have been, using only the neutral circuit, if that's how the appliance was designed.
Honestly, this is the biggest reason I even jump into these discussions. It's not so much that I don't think someone "could do just fine" by using a non-standard installaton, or even a dangerous appliance here and there. Your light would have it. It's the standardization that makes our modern code so much better than days gone by. With a faulty (or "custom") appliance, you have a "custom" appliance. If you break the system, you've broken the system.
