The first problem was easy and requires not comment but may be of interest to those new to sailing. Why anyone would put bottom paint on a rudder that retracts is a mystery to me. The paint on my rudders is so rough I am sure you would cut your hand if you swiped them hard. Seriously, for those new to sailing, keep those foils clean and smooth, 180-220 grit or better, at all times. Racers go to finer grits.
I think I know why owners bottom paint 26X rudders. They do it because they have to leave them lowered so neighbors won't complain of halyard - no I mean rudder slap caused by the loose fitting rudders.
I have aluminum plate stock that would provide a snug fit and I also have fiberglass biaxial cloth and resin that I could use to increase the thickness of the rudder. What do others use?
PS I talked to the owner of IdaSailor. He seemed very knowledgeable and anxious to satisfy. I asked about the failed 26S? rudders that Chip reported on. He said this was an early problem which has been eliminated. Their rudders are guaranteed for life and if they do not meet your expectations they will refund your money. Ufortunately my list of needs that cost $400 or more seems endless and rudders won't make the cut this year.
