I'm on ps4 and have no issue playing any job I don't rearrange buttons ever unless it's to get rid of non combat stuff like return teleport ect. I alway have them in order of level gained so the order they naturally appear in. Just feels right that way to me.

My advice is practice on a dummy while occasionally switching bar to see if anything up.

Worse comes to worst, you just aren't capable of playing the job which may sound harsh but it could be, I don't want it to.