You're right, Midnight, there's no absolute line that puts some complexities "in" and others "out."
No different from wargames, where the range goes from "beer and pretzels" games like Axis and Allies, all the way up to mega-grognard titles that literally track every ship, plane and pilot in the South Pacific (WTG Uncommon Valor!!).
And there's no sweet spot where everybody's going to be happy. We all have different tastes.
It seems to me that AH's philosophy has been pretty consistant -- maximal fidelity to the flight models, and other choices tilted towards playability. The formula seems to work, since everyone from the "beer and pretzels" players who say "I'll always suck at this, but I'm gunna have fun with my buds!" all the way to the furball forever gurus.
Limiting fuel to 25% = not fun. Lining up the perfect shot, but having your 163 explode randomly = not fun. Realistic engine failures or flameouts on that 262 your saving for = not fun.
Do this thread's suggestions add to fun? Not really, so I dont think they're going to get general implementation.
But, here's a thought -- what if you could get a 50% perk bonus by clicking on "realistic failures" like induced jams, engine overheats, no automatic WEP cutoff, etc? That could add to immersion for the grognards without burying the recreational fliers in unwanted realism....