1. Most Definitely and it is part of every work contract in Qatar. You can claim your gratuity for 2 years as it is calculated on yearly basis.

2. Certificate of Employee can be issued any time by the management upon request. As it does not cost them any penny. :)

3. Refer to your contract document. Normally in Qatar, standard work contracts includes the clause of paying air tickets to the employee to return to their country after termination.

Hope this helps.