Infantry Sections with vet and double brens do a sick amount of damage but it can be hard getting there. Some maps are much better (EG urban maps, lots of cover). Wide open maps will be a different story and I guess will require lots of sandbags until mid - late game.
Commandos have too much DPS although they are expensive to call in. I think their damage modifier when shooting from camo needs to be adjusted.
Should put it back to how it was where you could only deactivate it by retreating (at least I think it was like that). That way it is still useful but is easily to use grenades or vehicle crush.
Match maker will screw you over sometimes regardless of rank but it happens whether you are axis or allies. If you are a good player you rank will go up.
Try to talk to your team mate early on, find out what their tech / commander plans are are adapt to that so you have a decent combination. If they are lacking at then build some.
2v2 random has a fair amount to do with teamwork. If you don't want to work as a team you will have problems.