Sander,
I make all my string knocks loose to the string....from my experience that system is more forgiving of release errors, I believe that "snap" knocks actually pull the string past brace as they accumulate the force necessary to get off of the string. I have more consistant groups and accuracy with the loose knocks.....Just my opinion though.
I also used to align my heads for the vertical orientation, but no longer do so. If the arrowhead is vertical upon impact but hits a rib square-on it will still have to split the rib to penetrate and a very sharp 2-blade with a cutting tip will "bite" into live bone before it "slides off". So I quit worrying about it and since I use hardwood shafts the knocks and heads (hafted) are orieted 90 degrees to the grain/ growth rings. Again just one guys opinion
If ya think about it, if your distance changes as little as 2 yards you can have as much as a 1/4 turn so after I thought about it I didn't worry anymore....a good head from a good bow will cut the rib clean in half going in anyways......saved me a lot of brain fatigue. If I never kill another deer, I've probably allready got my fair share and haven't noticed any difference since I quit gettin all worked up over that head orientation. I'd be a liar if I said I had not given that question a whole lot of thought
My whole answer to the penetration thing, is arrow mass not head orientation. If ya get good mass moving it's gonna penetrate.
rich