people choosing off-meta, troll picks (like anivia "adc)
This is not punishable in any shape or form. Ever since Season 3, when I started, (and I bet money this extends all the way to Beta version as well) there has NEVER been any restricted pool of champs that are allowed to play in a particular role. You have always been able to pick any champ to go into any role without fear of punishment whatsoever since Season 3 (and I bet since Beta as well). This is how "new meta" champs are discovered. SOMEONE had to take that MF in support role or Shen in support role initially and frequently to prove that they can work. Forget about ranked, these champs are played in support role in the highest levels of play, the LCS, LPL, LCK, etc.
champs where they have no mastery or are "first timing it" in ranked
Having mastery on a champ is not an indication that you are any good at the champ. People may be practiced with that champs in bots, customs, pbe, in other accounts. People may have limited pool of champs they play well but either banned or picked forcing them to pick someone they are less used to not by their choice.
They then feed the enemy team
This is entirely depends on whether it is intentional or not. I'm sure you've had games where you absolutely murdered top/mid/bot/jg, whichever position you played. Looking back at those shiny high kda of yours, does that mean the opponent(s) you obliterated should be punished just because you played really well that game???
Being a support main, it also causes a lot of toxicity when adcs don't know how to cs and then proceed to buy cull and then not only continue to fail at csing and refuse to group
Being bad at a game is not punishable in any shape or form. What you described here is not trolling, but simply being bad at the game. If we go by bad performance, perhaps both you and I will be banned due to games we may have dropped the ball in some point.
There are also "junglers" that never gank and run to the opposite side of the map when an objective spawns.
Ganking is not a requirement. It is up to the discretion of the jungler. Bad jungles do not know how to gank or gank properly, sure. But that's also not punishable in any way. Perhaps you should learn to jg if you continued to have this problem.
They also flame you when you get camped all game but that somehow doesn't count as toxicity.
Based on my personal experience, I have NEVER seen a jg flamed any laner(s) for being camped. Usually it is the laner(s) that flamed the jungler first for their own failure to play safe or ward and THEN the jungler will flame. Perhaps if you experience this, you may want to reflect on what you say to your jungler first.
