Thanks Nic... I'm aware of the laws.

I'm seeking advice as to ease/cost of regular travel between these countries and whether immigration/customs want to see evidence of which hotel the GF would be staying in when she visits Qatar every few weeks........

I can't marry her before coming - even if we wanted to get married at the courthouse there isn't enough time. My job starts in 3 weeks and the courthouse requires one months notice of intention to marry (cooling off period I guess).