Hello Larry, lets concentrate on one thing at a time. The two counter rotating gears and the clutch disc are the heart of the entire assembly. I have many hours of use on my unit and I have never adjusted the position since the initial installation. That has been about a year and one half ago if I remember correctly. I suspect that you may have a gear that has radial runout or the teeth have not been cut uniformly. With the unit assembled and clamped in a vise you should be able easily rotate the input gear and shift between forward, reverse and neutral with no binding. I believe you mentioned earlier that you had to shim the axle, did this perhaps create other problems?
The dimensions of the axle, both diameter and length is very important for smooth shifting. When you add up the length of the outer axle, the end washer, and the circlip you should have a few thousands of end clearance. Probably 0.002 to 0.005 or there about. Next pay attention to the diameter of the bronze bushing and the outer axle portion that the clutch disc rides on. These must be very close, if the bronze bushing is larger in diameter than the outer axle the disc will catch on the lip. You should have a very slight chamfer on the clutch disc bore, this will help the shifting. Next the clearance on the disc inner diameter should be a few thousands, you do not want the disc to cant when shifting. Even with your 0.005" clearance on the clutch disc if the shifting fork is flat and true it should shift smoothly.
The occasional tic-tic of the disc hitting the pin is not a problem. Next pay attention to the shifting fork. This must be very flat, I milled mine from 3/16" flat stock. I only milled the outline initially. After the fork was finished and deburred I milled a very light recess (0.005-0.008) on both sides of the fork. This recess was large enough that the clutch disk would fit inside of it. The purpose of the recess is provide a little more tolerance for the dimensions of the gear stack and the detent position.
Start by making sure all of the gears are uniform have minimal runout. Then focus on the tolerance in the gear stack, clutch and axle assemblies. Then make sure the shifting fork moves without tipping to one side or the other. The pressure on the detent should be very low, I used a portion of the spring from a ball point pen.
Without being able to see the unit my guess would be that the rotation of the unit is a result of gears binding and the shifting issues are in a large part due to the shifting fork not being square when shifting is taking place.
Keep after it and let me know how you are doing. You are solving problems that other are likely to run into, your leading the pack so to speak.
Jim