I've kicked players for wearing the wrong gear!

[Nedkel]

Their playstyle doesn't fit with the rest of the party or my own at all. Therefore I am removing them from the party, which requires more people than just me, and if they get removed, that means multiple people in the party agreed we are better off without them. Not to mention you can circumvent that "restriction" by equipping the WRONG gear, for example having accessories for magical damage when you're pure melee.

End of story. There is no discussion to be had here.

You did not got what i was trying to explain here.
If someone has a gear that allows him to play X content and get into the duty, especially 50-60 or 70 lvl then you cant kick them because of it. Kicking someone because they are "undergeared" which in case of a roulette requirements are not, does not fall under the "different playstyles". Playstyle is not a gear you wear, its how you play your character.
In new ToS there is a line about "obstruction of play" which says:

"Obstruction of play" means all behaviour in general that obstructs another person's game play. Below is a non-exhaustive list of examples of obstruction of play:
・Improper expulsion voting
This means excluding another person by manipulation of expulsion voting.

This saying it clearly, you cant kick people freely out from the duty. If game allows someone to play X content then he is supposed to play X content, and there is nothing that would say someone is "not fit" for duty, if he could enter the duty he is most likely fit for it, game gives you a whole 120 minutes to finish it for this exact reason in case that the whole party would be undergeared. Of course it would depend on GM, but if you happen to kick someone from lvl 60 because he is wearing shinryu gear or something that line, he could report you and give you trouble. So you may want to not kicking people so often or at all for this exact reason, since rules are cheesy and it is easier than ever to ban someone, and if there would few people who would report you for the exact same thing, it is all in the GMs logs, they may look closer at you and grant you a prize.

Thats how mafia works ¯\_(ツ)_/¯