So, apparently the Alchemist's Strength Potion only applies to your first strength point- when you start the game. Otherwise it's just bugging out for me.
Heres a winning build, it got me to floor 15 on my first try.
Atlantian Reaper. Use items that have a greater total stat gain at first, until your unaided stats allow you to use at least one flash freeze and two critical strikes per encounter.
With Flash Freeze you can make sure you wont take any damage even when outnumbered, and the critical strike ability will let you drop the floor boss in just a few hits.
I have just added WASD.