Like I said before if you download this tuning guide it should be able to answer your questions. Here is a link to download it:
http://home.att.net/~sajackson/tuning_guide.html

When we say tune, it pertains to your particular setup. Your arrows, broadheads your draw length and your draw weight and your shooting style. you and I may have the exact same setup, but my shooting style is a bit different and cause me to do some different things tuning wise.

As far as your bow being tuned from the factory, it is NOT tuned. It is in spec. but NOT tuned. ONLY you can tune your bow. No one else can do it for you since like I stated before shooting styles vary.

Just take some time to read through the easton tuning guide. Trust me it should explain things very well for you. Also I suggest printing it out and keeping it very handy. Trust me you will find yourself refering to it many times.