I never had much problems with the possible inbreeding of elves in one tribe. That doesn't seem incestuous to me-- just the conjectures about close family members. When I mentioned incest as being shocking in another thread, I was referring to things like conjectures about Two-Edge and Winnowill. I really don't want to go there!
To me the relationship between Skywise and Timmain is distant enough that it doesn't bother me. On the other hand, I was bothered when Cutter and Skywise were casually talking about Skywise getting together with Ember. The blood tie wasn't there, to be sure, but the close familial relationship sure was!
But then again, I'm not an elf. :)