Taildragger, well of course we can't sit over here and answer a lot of your inquiries about the agency differences in a couple of sentances, let's just say that conditions have gotten better over here due to competition.
Agencies aside, it's impossible to predict which people will enjoy the atmosphere here without really knowing them well. All pilots now go to Hanoi, that is the policy, some negative opinions have been posted, I can tell you that after living in Vietnam for over six years, that Hanoi is a great city and I could be just as happy there, but now my roots are in HCM.
I feel your description of what kind of operation you'd like describes life here, laid back in comparison to Western operations, yes, not too laid back, yes again, and improving by the day.
Management is slowly improving all aspects of the operation, equipment, training, maintenance all are making improvements each year.
No need to do a lot of studying about the culture here, that is the best part of the experience.
You seem a bit interested in a rural setting, and near the airport, well you are in luck, since the airport is in the country side, most others live in the nearby neighborhoods of the Hanoi Sheraton West Lake. I think you would get a bit bored out there, but you could live there very cheap.
And as far as your budget goes, you could easily send that kind of income back and live a great lifestyle.
Cheers, D.L.