It is not unwise to have a doctor who is similar to yourself, especially one who is just a few years older. They have in recent memory personally tackled or investigated most of the issues that you are likely to start facing.
It depends. When I retired and moved in my early 60s, I deliberately looked for a doctor who was in his mid 40s. I want someone who is going to outlive me.
And someone who remembers me as an active, vigorous youngish retired guy. Not an old geezer on his deathbed.