I like where you are going with the name cleanups...I have been looking at the aircraft to see if there was a more "suitable" naming convention - and it isn't easy. Here are my thoughts (attempting to follow your example regarding "early" or "actual" names):
Airship - Airship
It's perfect, I'd leave it like this.
Early Fighter - Biplane/Triplane
This works great. We know what biplanes and triplanes are, and it gives us a sense of nostalgia for the pioneering days of early aviation.
Fighter - Fighter
I don't think it needs to be changed. This is what these aircraft were for. The only other alternative for me is "Interceptor", but honestly, I don't think it buys you anything. I'd keep it the same.
IL2 - Light Bomber
Now it gets tricky. This does collateral damage, so it is a bomber. At least, I would make that part of a naming convention...bombers always do collateral damage, and they do not intercept other aircraft.
Bomber - Heavy Bomber
Depends I guess on what you decide for the IL2. If you make IL2 "Light Bomber" , then I think "Heavy Bomber" is perfect here. If you decide for something else for IL2, then leaving this as "Bomber" seems most appropriate.
P59 - Attack Jet
Hmmmm. This one is tough. It just sounds like something that conjures images of the early jet aircraft of the '50s and '60s. The name "Attack Jet" just sounds.....retro.
Jet Fighter - Jet Fighter
I think this works fine. Can't think of anything that works better to be honest.
Strategic Bomber - Strategic Bomber
I like the sound of it. The big B-52 is what comes to mind when you think of "Strategic Air Command". I think of long-range, theatre-wide bombers that require significant effort to defend against.
Strike Fighter F15 - Supersonic Fighter
This tells me what I want to know. Since it requires supersonic flight, this seems like a good name.
Modern Fighter F35 - Strike Fighter
This one was tough, but when I saw that it got a +15% to City Attack, I figured that it is built to be not only a fighter/interceptor, but also a legitimate threat to ground targets. The military uses the "Strike" nomenclature to describe aircraft with ground attack roles.
A-10 Thunderbolt - Tactical Bomber
Hardest one for me.....this does collateral damage, but isn't a bomber (to me) in the classic sense. Still, for the purposes of what it does in the game - it unleashes a symphony of death and destruction on stacks of units. It has a short range and is built primarily to destroy certain types of units, unlike the Strategic Bomber, so "Tactical Bomber" seemed quite appropriate.
Stealth Fighter - Stealth Fighter
I don't think it needs changing.
Stealth Bomber - Stealth Bomber
I don't think it needs changing.
Aurora Scramjet - Hypersonic Fighter
Like "Supersonic Fighter", this tells me what it does, and what prerequisite tech I need to get it. Seemed like a natural progression.
Orbital Fighter - Orbital Fighter
I don't think it needs changing.
Orbital Bomber - Orbital Bomber
I don't think it needs changing.
Anyways, just some ideas. Keep up the great work!