when working your way up to the 70's try to rep a less as possible to keep from fatiguing the muscle. or drop down to 65,s and rep them out for a min, then jump back in the 70,s. ive ben stuck with...
if you want a difference with your body just start on a 3 day a week full body lifting routine. there is no reason do do any typ of prep. if your skinny why do you want cardio youll lose more weight....
thats normal for biceps, same for me if i train them aside from back day.. but i train them after heavy back and they do get sore to the stretch. hitting them after back reAlly breaks the muscle down.
no you will not be able to have biceps with no back, you wont have a big back with out legs and so on. the body has to grow together you will get miminal to no results trying to target only a few...