Welcome to the forum!
You've already gotten some great advice and feedback... I wanted to mention that I'm in the Twin Cities and would be glad to give feedback on my doctors and care.
I don't have experience with Dr. Cerny. My DaVinci was performed at the U of M Fairview hospital, by Dr. Zapzalka of Park Nicollet clinics. He has a lot of experience with the procedure, and it went well in my case. Dr. Uke, also of Park Nicollet, did my biopsy. Dr. Uke probably would have been my surgeon if I'd opted for open, but referred me to Dr. Zapzalka for the DaVinci.
As to your questions about hiking and backpacking... I'm about 4 months out right now. I've been lifting heavier stuff again for the last few weeks (such as bags of dog food etc, maybe 50 lbs). I'm not sure about carrying a heavy pack for a prolonged period though. I would think that hiking without the pack would be fine. I think I could manage horseback riding although I haven't tried it since my surgery (had a real nice ride near Steamboat Springs just before my surgery though). If I were to try riding right now I'd probably wear a pad as a precaution, even though I haven't needed them for normal activities for a few weeks.
EDIT: After reading some of the previous comments about horseback riding more carefully, I can see as it might not be a great idea... I would certainly check with my doctor...
Good luck, and let me know if you want any more info on my doctors or anything else...