I have a good friend whose parents are from Persia/Iran. He told me about this culture after we knew each other for quite some time. Even though he has never lived there, he often still has a hard time not to do this, which has resulted in some funny (at least for his friends) or uncomfortable situations over time. Knowing this, many things I ascribed to his character alone suddenly made a bit more sense.
When out having drinks, it is considered (1) rude to let your friend's drink go empty, and (2) rude to refuse your friends offer for a drink.
Is this accurate? If so... one can imagine how this can get pretty messy!
As for (2) I don't know any culture where if a friend asks you to meet up with them that there isn't some expectation you'll accept the offer and if you can't you'll at least try to make the friend feel you'd really like to but for whatever reason you can't right now. If you just responded "no, I don't want meet" I'd except after a few such responses you'd no longer be friends in any culture.