Here's my guess on what job five characters will end up with:

Jake: A police officer. It kinda fits since he protects the magical world, why not help fight crime in the human world too?

Spud: a teacher. I always pictured him as someone who's good with kids, so naturally, that's what I came up with.

Trixie: You need a doctor if you don't know this one.

Brad: NFL football player, who will come off the bench for an injured player, be a star, win three super bowls, then have them tainted by his idiotic coach with spygate saga: part two :P.

Haley: let's see, dragon council member, ballet instructor, part time rocket scientist, am I missing anything?