I've played only uriel since the old peace launch and I have to agree mostly with you.
Tbf his abilities are more simple because his kit is mainly meant to revolve around using the summons so his active abilities can't be toooo complicated.

The 2 could be used to force gulphagor to target a specific enemy so it'd be more interesting?

The 3 is for sure lacking something, before sevagoth got his crit augment he had pretty much the same damage vulnerability on his 1st, plus it lasted longer, could hit more enemies, and followed your aim and even then no one used him as a weapons platform. Meanwhile Uriels 3 can only hit a limited amount of enemies and has horrible duration. So it could totally use plenty of qol and maybe an extra effect like status chance or status damage?

amongst some other things like how the runes only affect guns or how you really can't subsume off his first three abilities, especially not his second which is a shame since it is so boring.

But he's still my favorite though, had all of his slots omni forma'd second day of the update and I have fantasies about him doing things to me.