RE: Three fingers under or split-finger method?
I shoot split primarily because that is the way I started shooting--I was several years into it before I saw anyone shooting 3-under and it had never crossed my mind to try it. I did try it a time or two, but it felt too unnatural. I don't have a problem shooting instinctive or gapping (which I do on long shots--40+ yds) shooting split fingers. A big advantage to me shooting split finger is I don't require a tight snap, or any snap at all, with my nock to string fit. Most everyone I have made a string for that shoots 3-under specifies they want their nock to snap on so it doesn't fall off on a downward angle shot. I'm not sure what you mean by arrow dragging or tipping?
Either way works, I think--one may work better than the other for some folks, just like some folks shoot a recurve better, some shoot a longbow better. I believe Howard Hill, Ben Pearson, and Fred Bear all shot split finger, Byron Ferguson still does, but I do know some excellent shots that shoot 3-under.
On the tiller, there is a verly slight difference in a bow tillered for 3-under vs split. In some bows there is a difference in bow noise, in some very little to none. Marc @ Chek-Mate has done some testing, and the tiller seemed to make no difference at all in shooter accuracy. The fellow doing the shooting (forget his name, but it was a big tournament archer) even shot a bow that was tillered upside down, and there was no change in his accuracy. If the bowyer knows his stuff, there should be no worries about the bows durability with one vs. the other.
Chad