As a HS/Juco PA announcer, I'll admit that in an exciting game, I might hang on my words a
little bit more when my team scores (especially on a 3-pointer), but not for that long. I'm from the "less is more" school of PA announcing, and try to not let any announcements linger too long.
One of my pet peeves is announcers who keep on talking in a FT situation after the ball has been put at the disposal of the shooter. If the refs are moving the game along quickly, I'll just work in the foul announcement quickly after the FT's, or if I can't get the shooter's name out, oh well. But I've never heard of a ref admonishing or being concerned about a PA announcer for the things the OP brought up.
As a coach, I'd be livid too if the music started while a player was at the FT line (although I don't think I'd slobber all over you.
) In my area for HS, music is basically prohibited except at pre-game at halftime.