Pinwheel 12 is right about the draw length.
Imagine if your anchors were the tip of your nose, and corner of your mouth (kisser for some). Adding a string loop doesn' t change ANY of that...just how far back your elbow is at full draw. Your elbow should be moving straight back on the shot, so 3/4" -1" shouldn' t make much differance...it' s still going straight back.
I like a loop because it should give beter arrow flight, is easier on your strings, keeps arrow on the string...even after drawing and letting down a few times, and it acts as a string silencer.
It doesn' t take me ANY longer to use a loop than shooting off the string. I use a thumb release...click it on the loop as soon as I am in the stand...it' s ready to go at all times, leaving my hands free for rattling or calls.
I do however use JUST a loop. no extra nocks or anything to space it. My loop is on so tight that to move it you have to spin it on the serving...and even that is tough.
I don' t worry at all about the loop pinching the string...I draw, let down, and check...NO problem at all. When you are at full draw, the loop may be pinching the arrow, but as the string moves forward, you are loosing the sharp angle of the string...this has the effect of pulling the loop away from the arrow nock (even if VERY slightly) so when the arrow actually LEAVES the string, it is no longer pinched.
Some shoot " fine" without a loop...I just know that the loop is more " forgiving" (I really hate that word...but you know what I mean).