Sounds plenty sturdy, but thats just speculation on my part. I watched my lathe sink through standard pallets without slowing down. The 2x6 pallets were just enough to get the unit moved one time. I had to rebuild the pallets with each move because they were trashed. Moved the lathe 3 times so far.
If I understand you correctly, you are wanting to leave your lathe on the pallets so that you can move it around? I don't think I would do that. While the unit is running, I would think the casters would allow enough movement to induce a wobble. That is just my opinion tho. That opinion does come with some experience I might add. I had a 10" on a stand with casters and it wobbled under power. If the machine is moving, it would be near impossible to get accurate cuts or good finishes.