Obviously forming fire team is a smart action to use as his first action?
Iīm still of the opinion, that FF isnīt a SA you have to activate.
I think it hops in automatically if you start your activation outside of CD....
So I think you can use your set of actions as follows
1 begin dismantling the HMG and do with the Orca as you see fit
2 disembark with the gunner and do with the Orca as you see fit
3 run with the gunner or shoot and do with the Orca as you see fit
You have only to declare when you handle the the crewmember. Either before the Orca actions begin or after them.
This then defines when you can fire/walk the Orca.