The best person to ask about your issues is your hand therapist. They are actually more knowledgeable with the effects of surgical trauma because they work with post ops far more than the surgeons. Personally I was so beat up I couldn't use my hand for so long my wrist became stiff through lack of use. Weakness? I had no experience with that other than if you don't use it, you loose it.
My advice would be to use your hand and arm as much as pain will allow.