Congrats on a new bow. 60# is a lot to start with unless you're a real horse, and it's not really needed for most critters. Keep in mind that with 60-80% let off, you were only holding 20-30# at full draw with your wheelie bow.
Split finger or three under is a personal preference thing. Have proponents on both sides,and each seem to rigorously promote/defend their way of doing it vis-a-vis the other. Regardless of how a bow is tillered, it can be shot either way.
I suggest you pick up a good book on traditional archery. It will answer a lot of questions for you and save you about 1,000 posts. Here are a few to consider. The Traditional Bowhunter's handbook, by T.J. Conrads, Timeless Bowhunting by Roy, Marlowe, either of the two books on Instinctive Shooting by G. Fred Asbel, or Shooting the Stickbow by Anthony Camera.
Welcome to the gang.