Electricity bill - u can give the number at present where u r staying, even if it is sharing its ok, no problem 

2nd - they will ask where have u stayed till now, and where r u going to keep the family now... for this only they are asking the house contract. 

3rd - dont say that u r going to stay in Bacheol accomodation

4ths- 7500 QAR salary is little less, cant u get salary letter of little high - may be around 12,000 etc. 

5th - keep ur degree certificate, employment letter and contract copy of employment

...

all the best,