For pan temperature: Just get an IR thermometer. Squirt a bit of oil in and you have enough that you can get a good reading. And then you don’t have to worry about making sure the oil heats up before you put the meat/whatever in. For something like a (cantonese street vendor style) stir fry you may want to superheat the pan to the point that the oil would smoke, but (regardless of what the people who hate electricity say) that is not the norm. And is generally very difficult to do indoors anyway.
Deglazing: In almost every situation, I would rather use a splash of a more flavorful liquid. Even a glug of chicken stock goes a long way. And I have definitely been known to do the “one for me, one for you” approach to booze while cooking.
Leaving an empty heated pan on the hob: Don’t do this if you at all care about your pots and pans. Or if you have pets or (stupid) kids. You are right in that “deglazing” the pan after you cook is a great idea. But I just use a glass of water to dump maybe a few tablespoons-ish in there, scrape it up with a wooden spatula, and then wash the pan. Pretty much every dish benefits from resting for a minute or two (at least) and that is really all you need to clean up.