It is not like it is entirely impossible that epoxy weakens because of being treated with traces of a solvent on the surface, but first: it is rather unlikely, second: you won't get any precise answer.
Thing is, it all depends on minute details and properties of the exact resin used, exact procedure used for curing, exact composition of the paint solvent and so on. And even if you were able to provide all these details (some of them are trade secrets, so it is quite unlikely you will be able to collect them), you would need to find someone extremally specialized to answer - most chemists do know basic rules that tell them more or less what to expect, but the only way to be exactly sure is to work with this particular substance and to collect tons of experimental information.
1. I wouldn't care.
2. The only reliable source of information is producer of the frame (don't be surprised if they don't know though - while they typically know how to make the frame, and they probably tested some paints and know that they can be safely used, it is quite unlikely they know _every_ paint and its effects).