Beast gauge gone in dungeon

[Niwashi]

That makes sense, next time i'll remove that stone so my hotbar goes back to marauder

That would work (but isn't necessary) if you're explicitly selecting a below 30 dungeon, but if you do leveling roulette, it could put you in either a below 30 or above 30 dungeon, so you'll need your job stone then. You can't change jobs in a dungeon or enter with a different one than you queued with.

And there will be later points in which your warrior rotation will change significantly when you get an important new skill, and none of the others after 30 give you a job change with a new set of hotbars. Level sync can change you to any previous level depending on the content you're doing, so you'll need to get used to using a subset of your hotbar skills depending on where you are.