[Hmm....]

Spoiler for HP recovery Item:

Actually, The only potion in the game is the healing over time potion. The quick-regen item is called healing crystal.
There is also another life saving item, a teleport crystal. As Aphrah said crystal-type items are expensive so people only use them when they really need it.

Spoiler for Trade and Crafting skill:

There are many player who live as a merchant and crafter in SAO (your so called skiller I guess)
blacksmith, tailor, leatherworker (perhap the same as tailor in SAO), Cook
There is even a player who live as information trader (no skill related to this job of cuz)

Alchemist haven't been mentioned in story but I'm not surprise if there is one.
I doubt crystals can be crafted though.