Can the employer ask the employee to sign a waiver before releasing labor dues?

I was terminated by my employer in Qatar after 10+ years of service without assigning a reason (which apparently is as per the contract). I have now transferred my sponsorship to another company in Qatar.

Question 1: My employer wants me to sign a "Settlement and Release Agreement" before they release my receivables including gratuity and 3 months salary and not including any severance pay that's not part of the contract.

Can they legally require me to sign the release (which is basically a waiver to sue them against wrongful termination and everything under the sun) to release my gratuity and notice period salary that's already covered under my contract?

Question 2: Also, under Qatar law, can an employer ask employees to work 6.5 hours a day during Ramadan for a 5 day work week?