Mount Rhoa should be a skill not clicking the Rhoa

Clicking Rhoa causes a lot of missclicks when fighting a small boss because Rhoa stands right next to the boss.

Gets even worse when you're playing with other minions, your mount runs off into a swarm and you can't call it back without calling all your minions out of the fight.

Agreed. Sometimes you have to basically run away from mobs just to trigger the rhoa into running back to you so can actually mount it.
It's really not solved in an elegant way and there should for sure be better way to control the rhoa, at least by adding a hotkey for mounting