This is a topic that kind of seemed 50/50 to me in Rebirth and I wanted to know what my fellow Assassin players thought as well in Adventures. I personally play the Knife build. Backstabs+Stealth+Poison+Base stat increases, with the healing potion on the side.
You definitely need to use potions. It is what makes the class what it is. Crowd controlling while single targetting with the knife. I use fire/ice to get that done.
I added the blast potion to my build, with epic it clears out all of the lesser minions like nothing so I can focus on the harder ones.
I got Lofton's Firebrand and it seems to add fire to all of your attacks, including potions. The hotkeys limit your skill choice by two, maybe three if you decide not to have a normal attack. I say have Lofton's firebrand, ice potion, blast potion, ninja stars, vitality, and stealth. Pretty much covers all the bases except for confusion. Still haven't tried how effective that potion is yet.