#1 I' ve used a True Taper tool without any of the problems that I have seen posted. As for being off center, I found that continueing to rotate the tool under pressure and using the proper guide tube will correct this problem.
#2 The gasket lacquer method has been covered over and over. I' ve used it and it works well for people that either don' t have patience or those who need their arrows in a hurry. (Shooting tomorrow) I think that Min-Wax is a better system. Gasket lacquer is NOT water proof, polyeurothane is.
#3 Min-Wax is at your local harware store. Gasket lacquer can be bought from hardware stores or archery supply houses. The gasket lacquer that I have used that was purchased from hardware stores, doesn' t work as well. If you use gasket lacquer, be sure to dip the tapered ends after you taper the shafts. Glue compatability is an issue with gasket lacquer also. Cresting paint too! Hope this helps somewhat. Dick