follow up on repair
Thank you to you guys who answered my initial questions!
I finished this fix and here are my observations on what caused it and what not to do while splitting the edge.
After removing the w-916 rib, the trailing edge didn't move one bit back to correct alignment telling me that it was my w-931 causing all of the problems! I did two things wrong on w-931: I didn't cleco it up and verify alignment prior to gluing and riveting. I remember the slightly malformed fiberglass wing tip not meeting the rib in all places so I therefore put a weight on it while gluing - this is most likely what gave the trailing edge the mis-alignment!
Now for splitting the wingtip. I first used a dremel cutoff disc(s) and this didn't work very well. It wasn't large enough diameter to penetrate the whole distance into the fiberglass end. It also is darn hard to keep aligned down that edge when you can't line up on it with your eyes to verify your work. I ended up basically butchering that edge with the dremel tool. Huge gel coat chunks were breaking off as a result of this initial cutting. The second tool I used was a variable speed jig saw with a fine tooth blade. I could line my eyes up with this saw and basically verify that I was cutting straight down the middle the whole way. This is the saw I would recommend for splitting wing tips!
Gluing: I purchased some 2" fiberglass tape. I stretched plastic wrap onto the aileron for protection. I also covered two wood strips (my clamp edge) with plastic wrap. I then roughed up the inside fiberglass edge with a dremel sander drum. I then put a large diameter dowel attached to a string inside the split tip so I could pull this out of the way once the fiberglass was in place.
With the wingtip clecoed onto the wing and aileron in proper alignment, I wet the tape with a straight mixture of 1:1 epoxy using a rubber squeegee. Note: the epoxy was mixed together for 2 minutes first! I also pre-wet the inside of the wingtip fiberglass with epoxy and then applied the tape to the inside of this wingtip. I folded this tape so the two edges stuck beyond the end of the wingtip in as straight of a manner as I could. I pulled the spacer dowel down and then clamped the whole mess together. After curing, I now had a new fiberglass backing to help fix my chipped gelcoat areas with a microballoon based epoxy fill. Applying fiberglass inside also allowed a fiberglass to fiberglass "structural" joint to be made. If I put this on the gelcoat, I wouldn't have had as strong of a glued joint. My long-ez buddies tell me that I shouldn't glue fiberglass onto gelcoat anyway.
Now this is a lot a work for not checking the alignment prior to gluing w-931. Hopefully I can prevent someone else from making this mistake!