I work for the hospital and I think there is always some sort of curriculum that one must follow when working in a hospital setting. The key is to take a look at that curriculum and find out if you can work within their guidelines.
I can tell you that the hospital I work for has good and bad. I LOVE my direct boss - she is very supportive and allows me flexibility, but that being said I have had some complaints from the chief of staff at one of the hospitals I am at because he wants me to teach mothers not to make birth plans, that inductions are good, epidurals are always good .... you get the point. He has threatened to veto my classes with his patients too, and right now my enrollment is low (not sure if it is him or coincidence). Like I said, my boss is supportive of me though as she knows I am teaching from our curriculum and not really pushing my agenda, and I honestly don't think our curriculum is that bad. I think it is way to short so stuff has to be crammed in, but I don't think it is horrible. The curriculum was set up to teach risks and benefits (pros and cons) of procedures, choices, birth, etc.
As for pay - I am paid by the hour. I am paid for my set up and break down time as well which for me usually means 1/2 hour before because I like to be early in case they come early and then about 10 minutes break down as I don't have much to take down
If you are interested in taking the job I would first evaluate the classes you are attending because most likely this is the same thing you will be teaching. I would imagine that the current educator is teaching from the curriculum that you will need to teach from as well. The next thing I would do is ask to see the curriculum and then talk with them about it - be honest about your concerns and see what they have to say. If they are rigid and you do not feel like you can teach under those circumstances then pass on the job, but if there is potential you will realize that when you speak with them.