Oh I love these all these gameplay ideas.
Personally I would prefer leaning more into the fictional world though. Something like the world of Strangereal from Ace Combat, allowing for more interesting and creative stories. Anyone who's played Ace Combat 5 or 0 will tell you about Belka.
And for the tactical mode, you may want to take inspiration from the air combat system of Xenonauts, its pretty unique and I like it alot, but air battles aren't the main focus of that game.
Anyways, whether you use these suggestions or don't, this game will become amazing. I'm looking forward to it.