Dear Massimo, full support and affirmation.
As far as breeding is concerned, we have a clear tendency towards your suggestions. But: It is necessary that at least some breeders try to breed special species/forms from time to time in greater numbers. Otherwise we could not satisfy the wish of beginners to receive these fish.
A specially successful form of breeding is practised by or friend Bernhard Lukiewski (Berlin). He has focussed his breeding-system on a few fish only, among them only one species of Parosphromenus (P. quindecim). He could offer fish of any age at any time. There has been no aspects of degeneration, although all is done from a single pair about 15 years ago. in other cases breeding has been proved to become extremely difficult from the third or fourth generation onwards. But I suppose this has been due to mistakes (less water changing, food problems, negligance) which the breeders were responsible for, too.
In general, your ideas match mine grosso modo. I wish you full success in Italy.