Is it against league of legends code of conduct not to listen to your teammates?

It is in certain circumstances. For instance, if all of your team wants to group mid and push while the opposing team has two dead and you are one of the carries, but you decide to recall at full health and mana with no gold to spend, I'd wager that's against the spirit of the game and teamwork. However, if some of your team is telling you to feed your lane opponent or demanding you give them buffs if you are the jungler, then you have every right to ignore them and keep doing your best to work towards victory. Remember, you don't own your teammates anything other then your best effort personally and good will to attempt to communicate and work together to ensure everyone has a good experience playing the game.

It's required but not for the whole game, you may just need to say a few things concerning the formation and strategy in which you wish to execute with your teammates but that's it. There's no need for any other kinds of conversations.

Yes I believe. At the end of a game you can report someone for it so probably.

It's situational. If you make repeated calls against what your team is suggesting and they don't benefit the team at all [or at times greatly benefit the enemy team, moreso than your own team], you're probably doing the wrong thing, and people will likely report you for it.

But, that's part of learning. If someone makes a call, and you feel like it's the wrong one, it might just be in their better interest to follow you instead. It all comes to you with experience.

I see this alot on my other accnts, and I wouldnt think the devs pay much attention to reports of "refusing to communicate" considering a decent chunk of the player low elo dont speak english. :/

good players, and those such as myself who are not that great but can think objectively, will notice you are doing your job the right way. so do not let others bring you down.

In all seriousness...LoL is so popular it is a 50/50 you will get a Trolling teamate in Summoner Rifts Blind and Dominions Blind...it really is...if u get into fight with any1 i just MUTE HIM lol hold TAB and a lil' Mute Button By the Champs Feed...Really it helps me zone in more and YOU CAN STILL SEE THEIR CAUTION CARFULS AND PINGS..so really thats all u neeed....I used to have Bands on my account but i found out Riot really doesnt like Cusssing or Profanity of any sort u__u but i cant help it...Just dont fight with ur whole team..then being Reported by 4 instead of 1 really hurts haha