questions to FSW and AEO's - help appreciated

Hello, I am new in this forum but what I've read so far is very promising. I hope someone can help me with my questions regarding my application for PR (FSW). I am just at the beginning of the whole process and those questions occur to me at the moment:

1. If my application for my permanent resident (skilled worker class with arranged employment opinion) is approved, will I have to work for that employer who made the job offer and if I do for how long do I have to stay with him?

2. In the Skilled Workers Class you have to collect those points (for education, language ability, work experience and so on) and reach at least 67 points in total. What if I have more than these points? Will it get me any benefit? Will my application be processed faster or is this 67 just a target value and after that it doesn't matter anymore?

3. Can you apply under two different categories (Skilled Worker and Candian Experience Class) and if so, do you then have to pay fees for each of them?

4. I have two possible job offers that I can use as an "arranged employment". One is in Ontario the other one in Manitoba. Can I apply for an AEO (Arranged Employment Opinion) for each of them or will that lead to a false impression or is it even not permitted? I just have two reliable companies (farms) that are willing to offer me a job as soon as I get my permanten resident staus but since it might take a long time until then I feel safer to have two job offers.
What if both AE's get approved?