And yes, some airplane engines use gas but the majority of them runs something that in constituency is closer to regular diesel than to gas.

Kersone is #1 diesel!

AV gas is another matter entirely but I'm not aware of any jet that would use it, though that might be a fun thing, and given that turbines can run on almost anything combustible it will probably work to some extent but I don't think it will be a happy ending unless the engine is really designed for it.

Btw, this is an interesting start-up: https://www.youtube.com/watch?v=ESdHyNtHpqs not cold weather but I'd hate to fly that in any conditions.

Still, I imagine that was a "light fire, move away" procedure!

Sure, small ones with piston engines. Sure. Most anything running a turbine uses Jet-A which is closer to kerosene / diesel than gasoline.

If you're leaking fuel you've got bigger problems than how to safely heat up the engine.

(There were some, late in the war, but only just. Otherwise, all aircraft were piston-driven, running avgas, a/k/a petrol / gasoline.)