So I kicked myself in the ass this morning and worked on it all day and evening. This is the Slums flag, it serves as a city entrance type of flag. I've decided to make a similar scenario as Karkand where you first have to breach the city and it's relatively narrow but once you've broken thru it branches out towards different flags and isn't as linear. There is a narrow road that goes into the city, you don't see it on the pics because it's not really done yet but this flag is to the right of that road and to the left is going to be a few houses with a riverbed.
There will be billboards but I don't know about the other AF assets. In theory I'm not really suposed to include the assets from expansions with my map but for small things like a tree and 1-2 buildings EA has better things to do and plenty of people do it anyway.
Unfortunately I'm leaning heavily towards scrapping the whole golf resort/tank battle idea and just making a similar scenario as Karkand where USMC has to attack the city. It's just a real pain to do and make it look natural/good and some things that I wanted to do aren't possible or people didn't find out how to do them yet. Like spawning vehicles as airdrops. The thread you linked is about making vehicles drop other vehicles but there is no way right now to make objects spawn out of a static spawner (ie where your tank or vehicle spawns on a normal map). It's possible to make both the parachute and the vehicle spawn attached but the problem then becomes detaching the parachute, it just stays with the vehicle all the time and makes it undrivable.