Hi Lens, this is my opinion on wedding photography for what it's worth
1. No matter how many lenses and cameras you have, you'll never have the right one for the wedding you're shooting. You'll always wishing for something else. The best camera and lens combo is the one you're holding. So you don't have a zoom, that's ok, you just have to walk more. I shoot many of my weddings with just a 35mm lens. It's more than fine for me.
2. If your friends are not paying you, I wouldn't run out and buy gear. a 50mm lens is more than enough.
3. I really have to highlight that wedding photography, at a fine art level, should really be an expression of yourself as a photographer. If you can't or don't want to shoot group shots, just let the couple know. They're not paying you, so you should have the freedom to shoot in anyway you want. Even for my paying clients, i don't shoot group shots because it's not my style. If you feel obligated, then shoot it, but if you don't feel like doing it, don't.
Hope this helps.