Can i sue ?

Yes. Consult an injury lawyer.

For someone who is based out of India now: Can i enter US , with a valid visa, if i have a pending case in claims court?

Shouldn't be an issue entering US and I see no reason why you wouldn't be able to sign a new lease. Consult an immigration attorney though should...

How does one determine a figure for emotional distress when trying to settle a claim? What should be included and considered?

I would hire a lawyer to look at all the facts and circumstances surrounding your situation. It is entirely too difficult and quite frankly...

How hard is it to prove defamation of character (slander) in a lawsuit or charges and is it an expensive thing to do?

Damages are key in a defamation suit. So the prior answer is correct if you cannot prove substantial damages than it is not worth your efforts.

Can I let an internet dating site know that one of the members has a restraining order against them?

Yes you can.

I drove a drunk friend home in his car at his request. Bumper was slightly damaged and I paid for repairs. Do I owe a new one?

You are not responsible for subsequent damage to the bumper.

Do I need to reimburse my health insur. comp. (or the dr.s they paid) for the treatment received from slip and fall?

If you receive a settlement than you're required to pay back your medical providers. Request their lien and they are typically negotiable.

What can I do to help protect myself?

I would advise your boss and/or immediate supervisor of what's happened and about the climate at work. Document your complaints in case you are...

Malpractice

It doesn't appear based on the facts you presented that you have a claim but if your convinced than I would consult with a Malpractice attorney....

Consult with an injury attorney to investigate the incident. I'm not sure what your suing for based on the facts you presented. Are you just...