DOR I am just about the opposite, I generally use 45-50 or 50-55 shafts for everything from 25lbs to 72lbs. I will agree that the lighter weights might not shoot quite as well from the really heavy weights. I don't know what you will use for feathers but I always use big 5 or 5.5 shield cut feathers and these seem to stabilize well even with lighter splined shafts, but I have never used any tapered shafts just the regular Port Orford cedars.
Have you ever read about or thought about using the some of the gasket dip finishes. I have used both think the gasket stuff gives a much tougher finish. I usually give them 3 or sometimes 4 coats. I usually try to dip 2 dozen at a time and by the time I have dipped the complete first coat I can start over so I can dip the whole batch in one setting and then let them dry and harden up for a day or so before continuing on. I also like the way gasket finish holds the fletching. With the poly finish I used either Bonning or Dueco for the fletch and would some times have them come loose and peel. With the gasket finish you actually use some of the finish thinned with a little acetone for fletch cement and while sometimes a feather would get torn up, I can't remember any peeling off.
Hey I really didn't mean to steal things or try to change your mind, but some times I just get started. Keep the pics comming, it will be interesting to see how some one else does things.