While I don't belive it is intentionally malicious, this is asking for an applicant to produce free work in exchange for the possibility of monetary compensation and no obligation on your part to extend a job offer.
Further there are no details on the job itself, including expectations or pay.
The alchemist is in the next book Core 2, they and the champion are getting big overhauls. The witch got a lot of changes and feels very unique compared to the wizard now; as a long time player and GM I've never had issues with the spellcastera feeling weak at our table.