Hi Pete,
the best way for me to know how hard to sheet, is the usage of tell-tales on the leech of the sail. If only the top one are absorbt, you sheet to hard. If the low one are absorbt you don't sheet enough. I had to learn that I have to use the proper rotation for a wing mast as well. A wing mast needs to point much more in the direction of the boom than a conventional mast and this will close the top of sail as well. I use the "poor man's split tail" as well and it is absolutly sufficient, but not as nice looking as a true splice.
Cheers,
Klaus