Midmac is one of the reputed Contrators in State of Qatar. If they have given you a contract, they will honour it. Let me give you my views.
1) Midmac camps are the best in Qatar.
2) Does not arise.
3) Upto you.
4) Yes Midmac pays good bonuses.
5) Alcohol is avialable in Qatar thru QDC where you require a sponcer approval and I dont think it will be allowed in Camp.

All the best and welcome to
Qatar.