@Arkandel This is what temprooms are for. Seriously. And if the game may be potentially set up to be mostly temproom-based anyway, it's not a huge difference.
I dunno how long it's been since you've appstaffed, basically, but, er. There are some winners. It's been a while since I've been appstaff anywhere, and while I'm 100% down with temproom soft RP, there's too much crazy out there to not give things a passing look-over before they are approved for play.
For one thing, this trusts implicitly that no one will make one of those banned concepts anyway and drop it onto the grid, thinking they have the best reasoning ever and they're sure to be an exception. See the 4chan troll and his insistence on that in a variety of ways -- this is sadly not at all uncommon; there are people who app as elders and just assume they'll be handed a giant extra pile of XP for nothing because they're old and would be playing accordingly; I've had people come to me asking 'hey, can I play a Strix?' and stuff there aren't even PC templates for. Someone asked if they could play a cat. Not a werecat, not someone with a spirit cat, just a cat. Meow. Some of this stuff is harmless, but some of it is pretty breaky, and even things that'd pass with minor tweaks could end up requiring some major retcons (which are a pain for all involved). People are accustomed to that with the kind of off-grid softRP that almost every game I know of permits, but if something is on grid, generally it's assumed it's approved, and I'm not sure it's a good idea to lose that delineation entirely.