Alternative heater to prevent bad things fom happining?

Yes and yes. They have been very accurate, what I set it on is within a few tenths of a degree of what my RKL controller says and what my high $$ digital thermometer I use for my work says.

 

Almost all heater explosions are due to being run when out of water. Sometimes it doesn't happen right then though. I read a thread on another forum of a stealth exploding taking out the glass with it and it was most likely because he let it run out of water during water changes every week, even though at the time of explosion it seemed it had been under water (hard to tell there wasn't a leak or something though since it shattered the glass).

I'd be more worried about the heater getting stuck on and get a controller that cuts it off if you are going to spend money trying to make it safer, unless it's 10 years old or something.