Radiation does not, in fact, cause heat. While infrared can cause heat, radiation does not. It causes the breakdown of atoms, more effective the less dense the atom is, which weakens molecules and through that cells, which is how radiation can cause cancer. The damaged cells can get infected. However, it does not, in fact, cause people to spontaneously vaporize
This heat was specifically mentioned to travel through walls, despite the fact that the Terebithia was heavily insulated using Metallic Glass, the strongest insulator known to man, in order to protect itself from the effects of the Exodus maneuver. This means it wasn't heat moving in a linear pattern, such as infrared, but the spontaneous generation of energy, or at least conversion of energy to heat energy, which defies any explanation.
The flames were metaphorical? I doubt it. He literally had fire coming out of his back after this happened, as well as the flaming wings. I really don't think they were metaphorical, and they were, in fact, magic.
Hot air mixing with cold air has a chance of causing tornadoes, but this is what occurs with massive shifts of air, global air currents colliding. The massive consumption of oxygen would cause all air to rush into the Terebithia, which is now a massive vacuum, meaning that a powerful gale would be pushing him towards the Terebithia, but would not in any way allow flight, or even gliding. The mixture of hot or cold air in such confined environments would not cause a tornado, as it would have no room for the reaction to start, esspecially as the Terebithia is moving downwards.

If you wanted Jack or the Terebithia out of the way, SAY SO! I was having a debate with Wraith about what to do, but he abandoned it in favor of roflstomping my character. I'd given him permission to kill Jack, but he also killed off all the AIs and the entirety of the Terebithia, as well as everything in it, which I'd specifically said were my backup characters for when jack died. He broke physics and all established rulings in the rp, as well as killing off Terebithia.

I'm sorry, but I find this incredibly rude. I'm fine with people asking me to back off with Jack, but to destroy everything like that without a word, esspecially using methods that break from the suspension of disbelief, is straight-out offensive. If this is the way you react to the idea of debate, or asking people anything, or the basic concepts of preserving realism in your rp, then you can go on without me.

Goodbye.