I've created a very flawed file and not sure how to fix it

I started down the road trying to model a robot like figure for the purpose of using it in some of my larger product presentations. Got pretty far into it then started getting warnings that the various parts were not good.
I used some parts from GrabCad and modified them and created others from scratch. Attached is the file…Any hints as to how to fix it would be appreciated.Female50%tilePoseStndg.stp.zip (12.1 MB)