I live in FL, so I see a lot of old people shoot. There are some that will burn you down, but there also a lot that are dangerous, and not in a good way. I saw one woman yesterday who should have been tossed off the range. Outside the range, she'll never get a chance to draw. A yute will body slam her into her car while she's trying to open the door and take her purse, her gun, and her car. A lot of people (Bill Wilson included) seem to believe they'll get close to an even break in a strongarm robbery.
As to age and shooting/carrying, do so as long as you're capable and competent, and have the wisdom to know when you aren't.