I love this question, @Lyannaa.
I think the main answer is that he is a great believer in image, he does good PR - and he lies, of course. Anyone can tell just by some minimal reading about him that he's a stingy, cruel, self-centered man. Anyone paying attention would notice that he has no real friends. Other politicians talk about their friends, often dating back to their school days. Trump only has sycophants and business associates. The real question becomes, why are some people so susceptible to his lies, believing the best of him, while believing the worst of Obama and Biden?
I think that your second paragraph is astute, although I might not have put it so harshly. I think many people, especially men, like the idea that he gets away with things a normal person could not - viciously insulting people, grabbing women by the crotch, sleeping with porn stars, cheating on taxes. But a lot of people do seem to enjoy his vicious attacks and cruel plans targeting "lesser" people - women, blacks, Muslims, poor people. And there is something authoritarian/fascist about it. Also, most Democrats believe that in large part, his supporters are just plain stupid. It's easy for anyone to see the blatant lies and petty vengeful actions - but it does mean you have to have a decent, truthful news source.
You're probably right about his family. Many people, including me, consider Melania to be a gold-digger, and he clearly does not have the warm relationships that other presidents have had with their families. As Trump has become even more unhinged, Ivanka has quietly removed herself. (Obama and his daughters were wonderful together.) I'm wondering what would happen to those relationships if Trump was convicted and lost all his money, so they had no inheritance.
By the way, I highly recommend the book Too Much and Never Enough, by his niece Mary Trump. She's a psychologist, and it's a wonderful combination of sharp analysis and fun family gossip.
www.simonandschuster.com/books/Too-Much-and-Never-Enough/Mary-L-Trump/9781982141479