Utility skills

Xmajson

Depends on how the engine can handle them. There can be things where you make open world puzzle/parkour locations for specialized loot or apart of the exploration that can utilize these skills or be what these skills are used for.
Like magic creating bridges, grapple hooks, ropes, etc. an explorer skill line designed to be open world exploration to scale mountains, caves, abandoned structures. Don’t know how that would work as a profession but could be?

Can have raid specific fights that require the use of utility skills like cc cleanse debuff cleanses. Channeling magic to create a passable terrain to the next phase of the fight. Something along those lines. Purges for certain mobs that are immune to damage and need to be purged.

I strongly think each weapon needs some form of kick/interupt and an immunity from kick with casting classes.

Taleof2Cities

Some of your ideas could very well be part of the Bard toolkit, Xmajson (cleanse, purge).

Intrepid hasn't done the Bard showcase yet ... which should feature plenty of utility skills. You're invited to tune in when they do.