concerning chapter 1.3.3 (Virtue Philosophy) of your book:
Do you really believe that masturbation and pornography (certainly provided
that it deals with voluntary sexual interactions between adults)  are major
human vices?!

They certainly don't ruin lives in the same way that other forms of intemperance do, but they still can be taken to excess. I agree that there is nothing wrong with masturbation and pornography in moderation, which is implied by calling it a form of intemperance. (However, I'm not sure whether any consumption of powerfully addictive psychotropics like crack or heroin could ever not be vicious.) So I would not agree that masturbation and pornography cannot be (or are not often)  indulged in to excess. One metric for this would be to ask people toward the end of their lives: do you wish you had indulged in more masturbation and pornography, or less?

there´s no reason whatsoever why consuming
porn ought to be generally considered "immoral".

I don't call intemperance "immoral", I call it vicious (i.e. a vice). "Immoral" to me has connotations of evil, and I think evil necessarily involves other people (via sadism or injustice).  Someone stranded for life on a deserted island could engage in vice, but not in evil or immorality.