RE: Epoxy CA hinges in place?
I'd be surprised if that worked.
CA hinges require CA to saturate the paper on each side of the hinge for a proper bond. Unless you get some MGS laminating resin or similar, I think that epoxy will be too viscous to saturate the paper AND the wood. For what it's worth, a fresh bottle of CA works best. I didn't realize this until I opened up a new bottle of thin during hinging an airplane recently; the fresh stuff wicked in ten times better than the old stuff. The old stuff was a month old at best- I build a lot of airplanes. If you're concerned about glue penetration, it may be worth your while to go to your LHS and get a 1/2 oz bottle of thin just for hinging each time you build an airplane.
Quality CA is another factor. I use Mercury/Flash and Zap exclusively. I prefer Mercury, but I don't worry about using Zap. I haven't really had luck with other CAs, but your mileage may vary.
I hope this helps!