that "safety button" you're referring to is the fuel cutoff switch, likely to have kicked in during the collision.
lol I couldn't figure out what those plugs were for either.... then I forgot to plug them in again. most annoying ride I ever had in the focus lol. that seat belt chime goes off about every minute, very persistent. and the airbag and seat belt indicators remain lit.
it's likely you may have to replace the seatbelt tensioners if they deployed their charge (i dunno what happned/was deployed)
if you start it up though, I'm about 70% positive you'll see the airbag light remain on.