A retired golfer has the time to practise the short game. Short shots don't require strength or flexibility. Certainly, the older golfer can't hit the ball as far as the younger player but once you reach the fringe of the green young and old become no worse than equals. Nothing sharpens your focus and improves your touch if you just use one ball in practice for getting up and down.
What the left heel should do during the swing has left many golfers with two distinctly different schools of thought. Long in the tooth coaches want the left heel to come up in the backswing and return to the ground at the start of the downswing. I'm old school and prefer the heel coming up, not that it produces a more classic looking swing (which it does) but because letting the left heel come up is the best way of obtaining a full 'free flowing' swing.
The important thing is that you don't consciously lift the left heel. You keep the left heel on the ground, but you let it naturally come up as you make your back turn. Top players, past and present, don't seem to worry too much about the left heel. It either comes up, or not, depending on the swing that needs to be made. In my humble opinion, keeping the left heel flat on the ground throughout the swing will shorten a player's period of success.
Out of Bounds: A person's character is learnt within just a few holes on a golf course.