The accommodation rental cost is major factor when talking about working and living in Qatar.
1small BHK will cost you the rental between qr3k to 5K. For 1bhk located at high end area such West Bay and Pearl Qatar will cost the whole of your salary, between 6k and 11k.
Share room is an option which you can hardly get between Qar600 to 2.5k if based on your offer. Your working hours, better refer to labour LAW or standards HR requirements. Good company they will not force you to work exceeding 48hours a week. So, if 10hours daily, working 6days a week, 60hours. By right the company should pay you overtime. Recruitment agencies should aware on this. And you can report to MOL, or relevant authority if your offers contradict with standard requirements. This is Just my personal comment. The best, seek legal and expert advise. Good luck.