I bought the launch edition on PSN and it comes with F-4E. There is also the Deluxe edition and pre-order edition.

Pre-order only content are obviously going to be banned(which I think the F-4E is). I don't think the Deluxe edition adds anything that changes single player. Unfortunately the PC edition isn't out so we can't compare it to the console versions yet, but I am hopeful we can use in game time and freely compete between all the editions.

Also I am waiting for the PC edition to play and have avoided spoilers so as I haven't played yet I'm not sure if there is a need for any special rules. If you have played a console version, do you think rules would need to differ from the AC4/5/0 ones?

I have beaten the game on PS4 (Hard mode) and probably needs different rules. This one is the hardest AC I encountered because of how aggressive the AI is this time and the number of enemy missiles from what I experienced and heard form others playing it. I'm not sure if restart from checkpoint will be allowed because it refills your ammo and many times I ended up emptying machine guns, standard missiles and special weapons where I am forced to use checkpoint in some missions.

I can already tell you that Any% isn't gonna be ran that often. There is at least an hour to an hour and a half of just time lost on just waiting for timers to tick down.

Individual levels will be the most ran. (Since you can skip the 6-7 missions that are 15 minute auto scrollers.)

As for ammo reloads: There are some mission that its just so beneficial to, like the second to last one. Then you have others that are check-pointed horribly. I'd be all for it personally.