ZoL was forked from Oracle ZFS, if you want the real answer you need to ask Oracle, presumably it was so that ZFS would be incompatible with their competition (Linux GPL based work)
I don't see anything that would make it specific to version 3, except that you might have to build your own version of gentoo. It would be nice if anyone else has an idea because I'd like to do this with the raspberry pi2 I already have.
Honestly ammo going off from a fire really isn't a big deal.Without a barrel for the ammo to travel through it has no chance to build up velocity. The casing is more dangerous than the bullet at that point.
For sure man, installing Nvidia drivers on Solus is a breeze compared to some other distros (I'm looking at you Fedora). Unfortunately I find Solus package repos to be rather lacking, but it works well enough that I use it on my desktop.