The thing I like about this game is it has a similar experience to the Zipper Interactive game MAG that was on the PS3, and I would probably say to look at some of their design choices- their selling point was the scale with 256 players at once, so what they did is have the action going all around, with the attacking team starting at the edges of the maps split up into platoons in each cardinal direction, capturing and destroying objectives to advance. More debris and cover for people on foot.
As for the issue of covering large distances, that might be hard to address without making things less convenient for the vehicle aspect of play- maybe add more vehicle spawns at once, or even another category of noncombat vehicles to spawn in just to get from point A to point B. Tunnels and passageways to bypass choke points would also be desirable, especially on maps like Kaleidoscope where a defending team can turtle pretty successfully inside a tower. Maybe add ducts we can crawl through?
I would personally consider the different playstyles different players might have, and consider how each might approach an objective. Give a couple ways to sneak in undetected, like the sewers in renewal or the tunnels in Kaleidoscope. Give cover for the people who like to take a direct approach. Large indoor spaces built like a maze are great when you want to get close and personal, but it's always more interesting if there's some way to slip a tank in, somehow. A security room where players can see what's going on and control doorways. An unfinished tower where defenders are at risk of being seen by enemy choppers- or one that the walls can be damaged. We love when things break, the more buildings we can demolish the happier we will all be
Maybe a map that is like a big sprawling complex- lots of interconnected buildings, big spacious interiors designed with intense firefights in mind. Plenty of skylights for some surprise air support, hallways wide enough that someone determined enough can get a tank inside, but enough side paths that people can still get around it. I want to feel claustrophobic until some walls start coming down
