Ok, you get your 8/10. I just beat the final mission and if you do it "right", it's really a piece of cake:
Fly ahead and ignore the spammy comments that call you back. Only use the fireball (first attack) and the nuke. Nuke big stuff, take out other stuff. The zeppelin made it with like more than 95% of its health. If I had not complained about it being too hard, I had said the opposite if I had tried the mission first with this approach.

I'm still not entirely sure what to make of this. Either (based on what you try to do, for example if you think it'd be cool to use your dragon-breath more) it's too hard, probably next to impossible or a real piece of cake. My suggestion would be to tone the defenses down somewhat or tone the offense of your dragon up but really force the dragon to stay near the zeppelin (like it gets shot down quickly if you move too far away). That way, you have to defend the flying thing but can destroy the buildings fast enough before they shoot down the zeppelin.

On the other hand it's a really tricky thing to balance and to get right and I also have to admit I never saw, in over 20 years of gaming, a truly working and fun escort mission.

If you promise to leave escort missions out next time I'd pre-order Divinity 3 tomorrow. Or some other Dragon-Knight-Add-On would also be nice (with more dragon flying, please). Any plans for that?

As for respawns: Maybe you can make it that you set them as different settings? Like a difficulty and a seperate "respawn rate" bar.