I haven't seen any except for school projects. It seemed like "being an artist" never came about until he pulled Sonichu out of his ass.
This was one of his first drawings of Sonichu, from 2000, so Chris would have been 18. It's exceptionally bad art wise and is a good indication that Chris never really did any character art prior to this. It seems like Chris "being an artist" only started from that project, the subsequent asspats for being so "creative" and just some comics afterwards.
As for Chris dedicating his life to art, I think it's a lot more mundane. Sonichu was the only thing that Chris put any creativity into. If anything, he's dedicated his life to mediocrity.