Free to waaagh is a shitty idea right now: orks population would explode. Those of us who have an ork as main character would be forced to queue forever just to start a fight. Imo the only thing to do is to fill the shop with cosmetics, lower the game price and attempt to monetize as much as possible through the shop (like planetside 2).
Matchmaker definitely needs attention, this is an extreme case, but really anything above a 2-3 man discrepancy means that one side has to play a good deal better than the other, and coordinating is just not that good by text, you just have to pray that you're playing with the better players of your faction or else it's just an exercise in frustration. Last time I played every match I either startes 5 men down against LSM or I was filling in late for a game where we started down pop, which of course with the timer system means by the time the game is fair you've usually already lost. I myself cut my game session off after helping coordinate a hard fought victory where we once again started off on the wrong foot, it's satisfying to do, especially when members of your own team start the "it's already over" stuff and you prove them wrong, but unfair fight after unfair fight gets tiresome quickly. As I said since before launch, the pop imbalance is one of, if not the, biggest threats to this game.
I think the biggest threat is rather skewed focus. If each faction was focused on equally, there would be less pop. imbalance and indeed, a far better game balance.