one word: Firewall...
I don't think its dangerous to route a fuel line through the cabin (well its more so than not doing it) but I think the concern comes from the fact it all looks kinda thrown together. The hose coming through the metal without a grommet, the pump doesn't look like it is mounted, the wires are kinda dangling. secure the loose ends and it won't be as dangerous. You might get gas on your friends legs!?!?!