Let me start by saying, this is not my own video. I wouldn't dare nitrate glycerol, and the finished product I guess is Unobtainium to me.
Anyway.. To the point:
In this video, he demonstrates and explains the properties of Nitroglycerin, and I found it quite interesting.
First of all, NG will not explode if it's not under pressure. Period!
If not pressurized/confined in some way, it will not explode!
I know, from other sources, that NG will burn very well. It's a bit more flammable than the alcohol we use in pyro, so not as "explosive" as gasoline.
It's auto-ignition temperature is 270 Celsius (518 Fahrenheit), and it does produce it's own heat by both friction and pressure.
Enough talk, here is the video: