I agree with the spamming issue, it's really really annoying... I wish there was a higher cooldown in that.
What I would like to see tho, it's the remake vote being replaced by a "fast surrender" vote, callable only before min mark 10 and only if you got at least 1 terminated player in your team.
Fast cc vote makes the losing team lose only 1/3 of the MMR and makes the winning team win 1/2 of the MMR... something like this.
In this way you don't penalize the teams too much, and also it will punish the leaver properly, since the game gets actually recorded (Current remake system makes the game not count at all, so any leavers, even if terminated, will not get punished).