1. Seems like Fuse and Ignition.
2. 22 what? Fahrenheit? Celsius? Kelvin?
3. There are a few things in TPT that are invulnerable like diamond.
4. A release of 500 pressure for a glorified Fuse/Ignition?
Unfortunately, I doubt this'll happen. You'd have to give an abundance of uses and have a more in-depth explanation on it. Really, it's just a more toxic Fuse.
That isn't going to be in any new update. The only reason anything can get by the pressure cap is throug console commands and lag spikes breaking the known cap of 256 pressure.
Also, like jacob1 said, explosives are hot. A 22 degree any explosive isn't an explosive at all.