Alchemist is more of a "Building block" craft in my eyes. Weavers/Leathers will love you for making dyes on occasion, and everyone has a need for glue or other alchemical byproducts as recipe components. It also provides you with a source of shards/crystals.

For damaging potions to be viable, they would first have to raise the stack size (and synth yield?) to... anything higher than 12. Either 99 or 999. I'm under the impression you can use the ailment poisons (paralyzing, blinding, etc) on enemies, but not sure as to their usefulness compared to the spells.