i think #3 is referring to the IVG, and it adjusts the tension on the main spring (large spring behind the hammer). i always start mine turned in about 2 full turns from it being flush with the body, then sweetspot the reg. if you can't reach the velocity you want you'll then have to turn it in more and re-sweetspot the reg again, repeat until you reach velocity. if you turn it in too far the gun will not recock and will leak. if you get to that point, and still haven't reach the desired velocity you'll have to start playing with different spring combos (i've always had luck with blue maddman springs).
read this for sweet spotting the inline regulator.
and this for a cheap valve tool if you don't already have one.