Another odd one is over tune new strings to get stretch, which often gets turned to don't put new strings on a guitar the same day as a show.
Well, call me a rebel, but I don't stretch my strings and I will go one stage 30 minutes after putting on new strings.
These are fine rules of thumb, I suppose, but as you are saying, a lot of nuance is involved.
The only thing I'll flat out disagree on is that old strings sound better... No just no.