Salleh...salary is relative to what you do for a living. Having said that you can be the best judge of how good or bad your offer is once you've done some research. DO a search in QL. Plenty of threads bout cost of living in Doha.

1. 2 br apartment 8500-12000 pm
2. Groceries for two 2500 pm
3. Water + electricity 500 pm
4. Telephone+internet+cable 500-100 pm
5. Car rental 2000 pm for the likes of Corolla/civic
6. School fees....sorry no idea
7. Other....no idea..depends what your definition is

Hope this helps. Good lucK!!!!!