Personally I would remove all non combat stuff from the 2 hotbars on screen (sprint/teleport etc.) so you can get used to switching between your main and other hotbars. As you level up you'll quite quickly start to fill up the 16 slots on screen. As an ARC/SUM I've never found MP to be an issue so I wouldn't put ether on, but worth having hi-potions there to get you out of a tight spot.