A series of questions involving the gpp dvd (strength training, planning, etc)

I plan on starting the workouts from the gpp dvd on January 19. I have several questions on how I should go about doing this though…

First of all, what is everyones opinion on strength training in gpp? I am 16 years old and have read numerous articles (including clemson’s boy to beast) on keeping strength training to bodyweight exercises during gpp. I have a pretty extensive weightlifting background however, so I do not know how this would play in. My strength training would involve lots of upper body depletion (pushups/pullups), medball work, weight vest training, and possibly rock climbing/kayaking. Would this be a good idea for the first 6 or so weeks of gpp, and then transition into the weighlifting the dvd shows?

I am going to be training until february, so I will have approximately 40 weeks of training. With that said, should the gpp phase be increased to the length of 15 or so weeks because of the extensive amount of training time that i have? It would not make sense to have 8 weeks of gpp and then 32 weeks for spp/pre comp. Or would it? I am interested to see what you guys think about this one.

Lastly, I will be on vacation at the beach during the second week of the gpp plan. Can sprints on the sand be used in place of hill work for this week? Or should I focus on finding a hill to sprint while I am there? Can tempo be done on sand (barefooot)?

Sorry for the extensive amount of questions, but I would like to make this off season a perfect one, and this board has an unbelievable amount of knowledge.