I would identify 'Assuming you are playing ready golf and you have identified and are at your ball, you are now "clear" to proceed with your shot.' as the later part of a preshot routine...The part of 'This doesn't include anything after your club making contact with the ball (this would be post-shot), or anything regarding driving/walking to your ball.' is where I would consider your preshot routine to start. The problem is most people don't start until they are already 'clear' to hit, which according to me is when nobody is likely to be injured by your shot, not necessarily when you are the farthest from the pin(unless of course you are in a sanctioned event). I like the analogy of the golfcourse itself is a 'think box' and the tee box is a 'play box'.
I loath 5hr casual rounds...no reason for it...lots of reasons why it happens!
It has become the commonly accepted period of time, known as the pre-shot routine, where a player is behind the ball with club in hand and is about to play their shot (i.e.: the time is ticking for a player that is ready to inbound the ball in the NBA, if you will accept that as a cross-platform example).
When you hear announcers, Golf Channel segments, golf shows in general, discuss a pre-shot routine, they're talking about the waggles, the alignments, the "stare down", etc. They're not talking about the walk to the ball, the club selection, the discussion with the caddie, etc. Don't read too much into it and get overly critical.