What would you tell them? I like a lot how the game is currently and understand how hard is to make decisions in such a complex game, but if they were looking for ideas and happened to ask me, the following list is what I'd tell them.

Additional signal wheel
From games like league of legends, you may press the middle button of the mouse and drags it top, bottom, right or left. In these positions you can assign actions, emotes, macros and such.

Official tab for static groups
Since end-game content can be frustrating for everyone, player skill and exigence over a challenge may differ (as well acceptance to mistakes/trolls), this tab would help especially players looking for serious groups and help to lower salt within the community.

Glamour for different classes
Some classes use the same gear, this can solve a current problem when you don't want your edgy dark knight to look like your heroic paladin.

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