I am unsure of how much weight to be using for workouts during the off season. Such as I do not know if I should be curling as much as possible or keeping it lighter as to not bulk up. The same goes for triceps and also chest presses. Basically my question is, using the reps and amount of sets in the TuffCuff book for the Off Season Phases should i focus on heavy weights or moderately heavy weights? If possible I would really like it if Steven Ellis himself answered this question.
Hmmm. I hear crickets.
Is there a customer support telephone number with the program you purchased or an email address you can submit questions to?
Perhaps you would get the response you are looking for.
My unsolicited advice would be to lift as much as you can without sacrificing any range of motion or over-exerting yourself to the point of concern about injury.
I personally never saw much benefit from lifting upper body weights to gain velocity. Improve your functionally stability by strengthening your lower half and working on balance. Most of the pitching delivery is spent getting from one foot to the other as quickly and efficiently as possible. Balance and having the strength to manage that balance from start to finish would be more beneficial than any chest presses.