I would like to see all HMG's reworked to reliably suppress blobs. Most HMG's feel unreliable in suppressing infantry, which should be their primary role. This promotes blobby play which is never fun. You shouldn't be able to charge head first into an HMG and kill it.
I still think squad formations could be spread out more to prevent wipes. Also, when a squad retreats or attacks it should retain a spread out formation better. For example, when attacking a tank with a rear echelon bazooka squad they tend to clump together which makes them an easy target. Also, squads that retreat sometimes clump up making them easy targets for tanks.
Much like mines, I think kill limits for most AOE weapons would be good and lead to less frustration gameplay. Big guns and heavy artillery should still be able to wipe squads in one hit. Things like grenades, mortars, and tank fire though should not be able to wipe a whole healthy squad in one hit.
Eastern front armies should be able to unlock buildings instead of building them with engineers. This will make things more fair and open engineer squads for buffs and/or reworks.
I would like the 2v2 map pool to contain maps that are overall larger and promote flanking. Too many maps lead to dead lock gameplay.
Flanking a heavy tank should be rewarded more. Maybe they should take 50% more damage when hit in the rear armor? Sloppy heavy tank play needs to be punished more, especially in team games.