Lisa, if I had your legs, I'd definitely be in golf skirt, too!
Meredith, your outfit sounds perfect. I don't think it's necessary to buy golf clothing unless you plan to take up golf yourself or find pieces you'll want to wear for other activities.
I can't speak for Lisa, but I think her leather sneakers comment was to steer you away from those multi-colored, neon athletic shoes which are so popular these days. A comfortable, classic tennis shoe with a good sole which won't cause you to slip on wet grass should be fine.
Private golf clubs can be quite conservative when it comes to dress codes, at least in my experience. That conservatism, however, gets thrown out the window when it comes to colour. I've had a hard time keeping from laughing when some old coot wearing pink and green plaid trousers with an orange and blue striped shirt starts ranting about dress codes. Golfers are the original maximalists!