1. First day usually starts on a Sunday. You can arrive in Doha on Friday/Sat.
2. Max wait is normally 6 weeks.
3. Try calling, good luck getting through. I don't see it being a problem.
4. No idea.
5. Friend of mine goes cycling 100 km each weekend. Go early morning, avoid the heat and go on the outskirts near Lusail where the traffic is less.
6. 777 working harder than ever with new bunk time rules. A320 working hard as always.
HTH