I spent nearly a month trying to negotiate an employment contract (a few yrs ago). at the time, I was out of work and doing my own consulting company (audio hardware and software). I had made a lot of progress and gotton a prototype made and was working, and I planned on keeping that side buisiness going even when I would start a fulltime job (probably just doing the audio stuff on weekends).
one company I applied for sent me the employment contract and it stated that anything I did while under their employ belonged to them. the business of the company was networking (and some java stuff) which had nothing at all to do with my product, yet they still insisted on owning anything I did. if I sold houses on weekends or fixed computers or stuff like they, it would be a violation of the contract and I'd lose whatever I worked on.
we tried making the contract fulltime (in the US, that means you get benefits like health insurance and vacation/sick time off, paid). they could not word it in an acceptable way. we tried making it a contractor form (none of the benes of fulltime work) and still they insisted on that clause. a month went by and my recruiter spent a lot of time trying to get them to compromise. in the end, I had to walk away since I did not want to transfer ownership of my own IP to them.
as for the 'not going to the bathroom during work hours', what kind of insanity is that?? even in the lowest of human rights countries, this is unheard of.
maybe you should move. I could not imagine even being asked to live in that environment!