Jothar:
You are basing all that you said on a “well-thought-out opinion of a rav”. Thats ONE rav and HIS opinion. He might have a lot of experience that does not mean that it is correct. Have you talked to any other rabbonim and found out there thoughts on this matter? Have you talked to marriage counselors? Therapists? It is very good that you are basing your opinion on someone who has experience in the field. But, personally, I rather have his thoughts corroborated by others.
Further, I still stand by my opinion, that couples have to learn to grow up and mature and stop blaming everyone and everything else. The internet and having other couples over as guests are just excuses and they are not the root of the problem.
And just to reiterate what Oomis said “Hachnossas orchim is a very huge mitzvah D’Oraisa.” I personally rather do a mitzvah D’Oraisa, then not do one becasuse of some rav who is being extra machmir.