I don't know about collecting, but there are virtually no regulations on freshwater sportfishing and no license required.
Like you said, I think you would have to go there and ask around. It's not even that there are Ecuadorian fish I really want, but we plan to go there to visit some old haunts and see a friend or two, and I would like to at least see some cool fish even if I don't ship any home. I also agree that nobody seems to know the truth for sure, but that certainly hasn't stopped the arguments over "F0" fish...
I am by no means saying that I know exporting fish from Ecuador is legal, but I have yet to see convincing proof that it is illegal.