In my opinion:
The point of still hunting is to see the game before it sees you. As such, a man like you isn't going to need a quick second shot. You can flatten a deer with most any centerfire caliber at still-hunting ranges.
The best practice for still hunting is still hunting. Squirrel season lasts 8 months around here, so a retired man can get really good at sneaking around in the woods if he wants to.
So: You need a .22 rifle that is also a deer rifle. That's a T/C Contender, with barrels in .22 LR and a short range deer caliber. I favor the .35 Remington, but there is excellent argument for the 7-30 Waters and the .30-30. .44 magnum and handloaded .45 Colt are right in there too, at close ranges.
Put a light scope on the carbine, and you're good to go at about 6 pounds (5.5 lbs. with iron sights).
Bolt rifles are the pure quill for long range shooting and high pressure loads - but that doesn't mean they're the best for a stalking rifle.
Anyway, that's my opinion. There are other good choices, of course. I enjoy my 1889 Marlin .38-40 a lot, but it's really kinda pretty to drag through an Ozarks briar hell.
Whatever you decide, I wish you the best in your retirement.
