8-man team should be more friendly to a new comer. Less troops to manage, enough variety, and leaves more space for upgrade.
Side door is very useful from my X1 experience. Glad to see it preserved.
Tilt-rotor is cool. And offers an explanation of the continent-crossing speed. Just make sure it has three wheels instead of four.
Both copter and fighters can be made flimsy or sturdy. Scout helicopter to Mi26, training plane to A-10.
But on the map I think they are both thin walls, so that strikes me as more realistic.
Personally I'd leave dynamic door for more advanced, ufo-tech-stealing crafts. Blame the slow hydraulic system of the low tech homo sapiens.