Few things.
1. no, heat won't effect it so long as you don't get moisture in there, you're fine. I'd use a dry heat personally, never liked the idea of water near oil.
2. Test E doesn't crash, it's not even able to crash. Once it's in a solution it's stable at even freezing temperatures. The hormone does not fall out and it can't bind to itself to crystallize. Maybe you're thinking of test c?

Not at all. Testosterone is brewed under high temperatures that exceed the boiling point of water. I am not a fan of placing a vial in boiling water because it will damage the label. Plus water contains a lot of bacteria. You'll need to make sure you boil the water long enough to kill the bacteria. You'll probably want to wipe the entire vial down with rubbing alcohol afterwards. There is a remote possibility that water will seep into an opened vial which would be very bad. You won't be able to vent the vial while heating it so the vial will burst if not removed in time.

I personally place the vial on top of a skillet at medium heat since I have a gas stove. I do not walk away while the vial is heating. I monitor the vial during the whole process. I am watching the crystals break apart and dissolve. I am also watching the liquid contents level in the vial. I don't want to oil in the vial to reach the stopper. That is close to the point where the vial can burst. That isn't a pretty sight. You''ll have oil dispersed all over your kitchen. If the vial shatters, you'll have small pieces of glass everywhere. You can vent it but you need to be careful about that too. Oil can leak out of the vent if you aren't careful which is why I don't vent.

You don't need the water to be boiling. And I'd doubt that it would effect potency. May need to put a 25g pin in the rubber stopper to let pressure out, last thing you need is the stopper blowing off with hot oil flying everywhere lol.

I say even if it did reduce, by really how much? If your bottle is crashed would you rather inject it at 2-3% less potency or throw the bottle away and not inject any of it? And i wouldnt waste time or money to test the bottle after heating either to really find out. If you doubt use that money and just buy more and double the potency.

Nope, pin away.

After it cools a bit.....
Using a wax warmer is a good way as well. Not that I have a wax warmer..or potpourri in every room...scented hand towels..

Nope. The melting point is 311 degrees.