When it comes to Life Potions and Power Vials, I can't select it to place it down. I like doing that, and it stinks.
Also, placing down Potions for storage doesn't seem to have an actual purpose, can you make it so you can't rest while Potions (Water Bottles, Mana, Life, Power Vials, and Greater, Further, and Advanced variants) are on your person? Using the counter space for storing Potions implies there to be a limited backstock you can have for Potions, which I'm sure is a little interesting gameplay-wise.
Oh, and why not have the ability to drink Life Potions to regain Stamina, since you do lose Stamina from "over-collecting" Slimes, and potentially other tasks in the future? Sounds solid to me.