First off, the simplest one:

Skills need to be splittable. Both for accessibility reasons (I use the locations of skills to help me remember positionals, not having this is why viper is nearly unplayable in pve for me even with workarounds) and to prevent wipe-causing misclicks (if the target isn't swapped when i try to 'voke after protecting a healer, if they're the last one up I've just killed everyone with a misclicked shirk).

Second:

Unnecessary/harmful consolidation of skills. There's generally a lot of consolidations that indicate a lack of familiarity with the actual situations people encounter in the game, like shirk/provoke and low blow/interject (the latter of which are not related concepts and do radically different things and in deep dungeons often need to be used in very rapid succession), and it feels particularly bad as a tank main to see my main role designed apparently by people who do not main a tank.

Third:

Removal of skill expression sucks. It just does. There's no way to avoid optimization, because that is not how games that use math function. Needlessly removing the need to make choices about when to use something sucks, and it's disproportionately impacted support players here in a negative way. An example is things like removing the ability to do something like 1212 clemency to save a run, but also if I eat dirt and I know I'm going to, slamming a buff to help my party just feels better than eating dirt and having to suck it up.

I haven't been able to heal much due to framerate problems, so I will leave healer commentary for healer mains, but I have seen complaints from a healer main so I know it's not just tanks. I'm also struggling to remember other details that I may have overlooked, so i welcome feedback there.