Hi, Penny. Sorry to hear about the problems with your new house. I'm not sure I understand exactly what is going on with the doors, but it sounds like the walls might be out of plumb. Check this with a level. Some tile people like to put a slight crown on bathroom floors to have any water splashed out of the bath run back toward it but this crown should be almost impossible to detect. If it is more than this, it certainly is a defect.
There are 3 things you should do to start the process of getting these thing fixed, and the process will no doubt be long and bumpy. First, read the contract/bill of sale to see what it says about guarantee/warrantee and the process for getting things resolved. Follow any process that is included if it conflicts with what anybody tells you about how to resolve the problem. Second, send a registered letter to your builder outlining the problems that you have found. Your terminology may not be correct, but do the best you can and don't forget to keep a copy of your letter and get a return receipt. Third, check down on this board to see what others have suggested about dealing with contractors. There is some good info here already.
If you used a lawyer on the sale, send him/her a copy of your letter but give your contractor a fair chance to resolve any problems. If you are obviously not making progress with your builder, get your lawyer involved.
Hope this helps and you get a resolution. Henry in MI