Wow! I've done some jackknife carpentry myself, but never anything like that. I'm not personally experienced with tile, but for what I have been lead to believe is the floor must be rock solid before you can lay tile. Any movement will cause cracks. Also, because tile is quite heavy, the under floor has to provide a lot of support. I'm sure some of the guys with more experience with tile can elaborate on this. I don't see how being a little out of level would be a problem with the tile, but it could cause water to gather in a corner which would not be too good. My thought is that vinyl would be a better choice. The self leveling stuff may be a good option for vinyl.