Definitely immorality. However the fact that he has made out of court settlements numerous times in advance of court cases, most recently with Trump University, would suggest a significant level of illegality also, albeit unproven.
For an insight into his character this is worth a read:
http://www.newyorker.com/magazine/2016/07/25/donald-trumps-ghostwriter-tells-all
He settles out of court, but only as long as there is a non-disclosure statement signed. He actually brags about that. Unfortunately, in some of the cases his lawyers have not been able to get all the paperwork sealed, so actual actions and testimony are known.
He is a two bit snake oil salesman who convinced a few big banks to give him money (with his father as a guarantor), and then fucks everyone up and down the chain using the old nugget "if you owe the bank a million bucks, the bank owns you, but if you owe the bank 500 million bucks, you own the bank!"
His father, whom he adored like no other (except perhaps Ivanka...so hot I'd date her if I wasn't her father), was a racist sheisster before Trump could probably for,late that sentence. He went to a two bit school, until his dad got him into a better one for the parchment, then just proceeded to do what the old man told him, while bailing him out at every turn, on every crap deal he ever made. His piece de resistance was Trump Tower, as it was actually in Manhattan, whereas their slum lord apartments were out in the boonies of The Bronx, etc... DJT thought that made him a player, and in the days of ostentatious glitz that were the 70s and 80s, he became a player, even though the old money despised him. Even the father of his son-in-law went to jail for crooked real estate deals (take a peek at that story!!) and now the son is married to Ivanka and in charge of Israeli-Palestinian peace? As a strong Jew, not hard to see where that particular path is leading!
He is a huckster in the absolute worst sense of the word, and has been able to pay people to kowtow to him, because he acts like the The Big I Am at every opportunity. He is a loser who is trying to cover up for all his flaws by being loud enough to convince other losers that he is a winner. He just says it and says it and says it until people believe it, but the people who REALLY KNOW HIM AND HIS BACKGROUND KNOW IT IS A FRONT AND HE IS A BLAGGER!
He is a cnut of the highest order. Now, though, he is a protected cnut of the highest order, for the rest of his life, unless he does something really stupid and commits a felony that relieves him of office. Even he shouldn't be that stupid.