I'm an ENTP.
I've flown with a bunch of guys that are very obviously 'I's. I also reckon that the majority of people I fly with are 'J' rather than P.
So at least that answers your question about QF only going for ESTPs!
PS: Some of the better skippers I've flown witih are 'F' rather than 'T'. A much better CRM environment generally. I have to work a bit harder at that one!
Hope that all helps.