I dont have much trouble dispatching those bandits on the way to the battle tower as you mentioned. I eliminate them all while I still around lvl16 or 17 with bow Mr Shooty easily in hard mode. My bow crit damage can reach 300 around that time.
There are various ways to clear enemies and if you find them tough, just lure the enemies out 1 by 1 and dispatch them easily. If you still find yourself unmatched for them, then its time for you to upgrade your equipments.
Level can easily be gain by just killing mobs only. I currently reach lvl 18 without turning majority of quests in broken valley. I think I just turned in bout 10 to 20% of the total quests in broken valley and sentinel. Havent set foot on orobas fjords as well.
