Honestly - hot glue is best. Epoxy imo wouldn’t flex enough. Hot glue is used by many top paddlers to glue the blade into the shaft. It’s strong enough to go out in surf. Plus it’s easy to re-adjust
There’s loads of techniques for frame prep and it depends on the condition of the frame in the first.
Yes - precision masking is amazingly accurate if you find that some parts won’t dismantle easily. You need high end tape though and brand new scalpel blade