Players who only play with white

I agree with #1. I also have seen quite a few players who played white only. I normally block them and think that it is kind of "rating manipulation" at least, since they got unfair advantage (1st move) more often that it is statistically allowed in the game of chess. But probably the idea of prohibiting such behavior on lichess is not very popular, so just keep boycotting them.

I get it when people try to practice a particular opening, but as @Alex_slow pointed out: in rated games, they have a consistent advantage (and we would have a consistent disadvantage, playing all games with black).
For instance, I have 2 opponents that I have played over 12 times, 12 times where I played black. I just think that there should either be a way to penalize those players or exclude this option from rated games.