"You have a point about safety as it relates to building code."
This reminds me of the original Geo Metro, a car which was advertised under the old EPA guidelines to achieve 55mpg. I very much doubt you could build that car today as it wouldn't meet current safety requirements but I don't see how it's more dangerous than a motorcycle which is completely legal to ride down the highway.
Safety is always a good thing. As far as these houses go, one of the primary reasons that many of them are built on a trailer is so it will be treated like an RV instead of a conventional house. So what issues would these houses have that you wouldn't encounter in an RV? My understanding, and it's entirely possible I'm dead wrong, is that there are certain standards RVs are encouraged to comply with but there isn't an RV specific building code per se.
So the two sides of this coin as I see it 1) countless people live in park models and every kind of RV and never have a problem, and 2) when RVs burn, they burn quick.
I think it's easier to make a tiny home more fire resistant than an RV. For starters, you can add fire breaks in the walls and if you don't plan on moving it or are handy with mud, you can use dry wall.
As I previously mentioned, for going solar, I like the idea that I can run my LED lights off of 12v DC in this scenario instead of having to run all of my juice through an inverter to run it off of 110v AC thereby losing efficiency. If I wasn't planning on using solar panels, I wouldn't even bother and would just wire everything to conventional building code.
All of the mini houses I've looked at online seem to have plenty of windows so egress during a fire doesn't seem to be an issue.
If you don't put up a fire/CO alarm, you're obviously trying to become a future Darwin award.