The one that bugs me is "hobbiest".
It's hobbyist. Unless someone is actually trying to suggest they're more of a hobbyist than anyone else, in which case they should drop the "hobbier than thou" attidude.
Actually it would be someone that is more of a hobby
, not more of a hobbyist
. (hobby, hobbier, hobbiest, similar to funny, funnier, funniest).