There are some karma based systems in other games where the good players (skill, communication, being nice) are rewarded with some in-game content and bad players (toxic ones mostly) don't get any kind of thing. A system like that would encourage a better behaviour, but it seems there is no real intention to consider this kind of alternative. Sadly.
1) You can't report opponents by in game tool, for verbal abuse you open a ticket which is correctly evaluated by some WG staff. Reports over teammates are still a thing.
2) At the end of the game you can assign a karma point to a teammate, premade or not. This on every game you play. If a player assigns the karma then he earns a small reward (credits? flags? camos?), if all players/a majority do that the reward is boosted for everybody in the team (+x% credits, +1 flag, +1 camo). Once a player reaches a certain score on one of the ladders (skill, sportmanship, leadership, friendliness) that triggers an additional reward (something more unique like a special flag/premium flags/good camos/doubloons). Ah, when somebody has a good point base on one of the ladders this is shown in the loading screen, allowing all players to know that [player1] is a good sports, skilled or whatever else. This brings to players actively trying to behave in a better way. Toxic players will stay toxic, others will slightly improve allowing the playerbase to raise the minimum standard. If good behaviour is rewarded MAYBE there is a slight incentive for all to behave better.