Q2, absolutely take the measurements and record them. What I take notice of is many guys get their string changed by a shop and then ask why their bow is shooting differently. Well, how many places measure everything beforehand and set it up the way it was? If the cam is not in the right position it affects drawlength and bow weight. Even different string materials shoot differently ( 452 vs 8125) A person should know what material his string is made of too. A string is not necessarily just a string.