Obviously the keys and ID are the company's property so return those as requested. As for the release forms, I would recommend you visit with a Board Certified labor & employment attorney before you agree to sign anything. Simply obtain a copy of whatever they want you to sign and take that with you to a visit with an attorney. It may cost you a small fee to visit with someone who is board certified in this are but it is a far better option than simply signing off on a release without knowing all of the implications or knowing whether you may have a viable claim against the company.
Hope this helps.
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