There's some impressive ideas here. Love the racing manager one, that would be immense!
I'd probably have a few!
One being what I really hoped Test Drive 2 was going to be. A massive open world where you can drive around, race others etc, but when you got out the car you could interact with other people a lot easier, e.g. when you're in the same area like a garage or a house you could talk via headsets and all in that area could hear, with little mini games you could play like in the bars on GTA against each other. Unfortunately Test Drive had the worst connection issues so failed on me, also the limits to what cars you could buy was annoying, I think as long as you can afford it you should be able to have bought it, also I'd want the driving to be more like Forza/GT.
Another I would like is mainly all I feel Final Fantasy need to do (big fan of the game series) I found with their new battle system in FFXIII if they used that but had the brilliant open world exploration of say VII, VIII and IX, with possibly the card and blitzball mini games would be incredible, but also to be able to play with up to 3 friends, so your characters are slightly created, and you can opt for agility, strength, white or black magic as your selected level up path. Maybe you choose one main and then a secondary, so you are more agility but also have white magic to cure the team. I think that could work really well.
Also that ArmA game looks amazing! I need one that good on consoles so I can play as I dunno if my computer to cope with all of that.