RE: anything wrong with carpenters glue for joining wings?
My experience has been that there are just a few places on a plane where eopxy is an absolute must. Joining wing halves is number one and wrapping a strip of fiberglass cloth about two inches wide around the wing before applying eopxy is even a good idea. The epoxy can then be heated and it will flow into the cloth strip and make the joint a permanent bond. Wings have folded up in flight because the wrong glue was used. The other places to use epoxy is where the firewall joins the fuselage and both vertical and horizontal statilizers. You don't want those surfaces coming loose in flight. There are other ways, I suppose, to do these things, but this way has proved effective for the last 60 years or so. It's a good idea to use 30 minute stuff in these places because 30 minute eopxy is stronger than faster setting epoxies. Slower setting stuff would be stronger yet, but 30 minute seems to be the best balance of setting time vs. strength.