Can my parents obtain custody of my niece?

That would depend upon a number of factors - and can't be determined just from the information in your post.

Can Family court make a judgment against me to pay more for my daughter's college tuition than I can afford.

The divorce settlement controls unless it is altered by some form of petition in Family or State Supreme Court.

Can a biological father get temporary sole custody of a child ?

Under some circumstances, yes. you should discuss the situation in detail with a local family law attorney.

How can i obtained a criminal background report on my son's father for a change of custody?

There are any number of website that offer such checks.

I am non custodial parent I have my daughter for the summer, how long can her custodial parent ignore me before breaking the law

You can take legal action at any point. Consult a local attorney in the town in which the child lives and discuss the situation in detail.

Is there any document that allows you to put property/home in your kids name while protecting it from divorce or bankruptcy?

You should discuss the situation in detail with a local estate planning attorney - you'd have to be careful to avoid fraudulent transfer issues.

How much support is my ex-husband required to provide and for how long?

There is no set formula and the amount can't be calculated without a lot more information.You should consult a local attorney and discuss the...

All you can do is follow procedure. If you don't have a local attorney - get one!

What could happen if my ex carried me on his health ins. after being divorce for 2 year?

Technically it's insurance fraud. Whether there's any significant problem is likely dependent upon whether there were any large claims paid. You...

Lack legal representation before signing a marital separation agreement.

Not necessarily - but you should have it reviewed by a local attorney and discuss the situation in detail.