It's not I have nothing against variety, but I suggest we remove competition between players altogether or stay to core classes. Things could get kinda messy and unfair. Of course, if this going to be a happy romp as one close-knit(more or less, I expect the chaotics to not agree with the lawful, etc) party, then no worries.
Oh yeh; what about pets, familiars, guardian spirits and companion animals, et cetera? Any restrictions?