Debugging allows for you to trigger a meteor, and you can click anywhere you want, so technically you could have one crash on a sim. I did a random meteor strike this way, and Mary Baker happened to be within range of the meteor, and got her ass burninated. She still hasn't cleaned herself up after a week. I also managed to blow up Brunton's Boxcar Diner. Whoops. No sims were inside, so I don't know if they would be exterminated, or just burninated.
As far as sims torching themselves when inventing, I used the AM test to add the hidden trait "Immune to Fire" to my sims, and they have yet to torch themselves. This could just be luck, I'll have to test it out more.
I tried to add that trait. I'm assuming I did it right when I got the "yay!" message. They still burnt themselves to a crisp. There's now four ghosts roaming around on that particular lot, which makes it kinda fun for late night inventing. YMMV, of course, but I take no chances and have a shower usable within a few squares of the inventing table.