RE: Tree Stumps?
Ditto what timbercruiser said. That would be your best bet for sure. I'd spend the $ and have someone do it now, rather than later.
If for some reason you feel you can't do that, and you don't plan on ever doing it....dig down around them and take a chainsaw and cut them flat with the ground so you can at least mow over them. Of course you'll still probably not be happy next time you go to work that plot up. Good luck.