If your suggestion of a sticky is a checklist for posters asking for machine advice, that is a good idea.
A couple of big ones
Available power and if 120v only, is 240v a possibility in the future (a budget item vs a hard no for other reasons).
Access, big differences between a dedicated outbuilding, a garage, an outside accessible basement vs inside only, a spare bedroom or dining room / kitchen table.
Space is a hard one, as most vastly underestimate the space they can find when properly motivated.
Living situation, is one I think is very much over looked. A person who is in their lifetime home, so a one time move in is very different from a younger person starting out who may have multiple moves ahead of them. People do get 3000lb machines into basements, but nobody wants to do that twice.
Probably most important, why do they want the machine. Clearly many are satisfied with small machines or there would not be so many being sold. I also think a lot of the small machines get kind of an undeserved bad reputation because people buy them because they fit their space / budget. Buying a 7x12 mini-lathe to turn truck axles simply will not turn out well, and that is not the fault of the lathe.
We have a lot of members who have some very nice shops, and we have members who have decades of experience as a hobby and in many cases professional machinists. We also have members with tiny shops, small machines and minimal experience. I think we all carry our own bias when helping people choose a lathe. When a new poster shows up providing little information, that makes it really easy to look at each of our own situations whether that is a 40x60 shop with 12 foot ceilings or a space tucked away under the stairs with an extension cord for power.