I can accept it on a couple of conditions...
1) Can we assume that appearance pic no longer really works then? I mean good reference, but I doubt a 16 year old half goblin looks like a hulking death machine, the half elf side would only make him about average height, but he's still a slender build.
2) I'll take the background, but lets assume turning into a tower of fire was a rage thing and that he can't do that on command. Like you said, he's a jack of all trades but that means his skills are only amateur at best and turning into a pillar of fire is some advanced magic.
If you accept these things, which don't need to be adjusted in your CS (I can do that when I add it to the cast list), then you are accepted and can go ahead and join us for breakfast.