Well, covering the whole Littmann-Story could easily become the longest post in the history of this board (even longer than that about Orwell

).
I'll try to make it short as I'm quite sleepy and need to go to bed:
He's not so much of a business man, but of an artist, who is a business man as well as he founded and still runs two privately owned theaters, a restaurant, a gay bar and together with partners the Spielbudenplatz (the place in the middle of the Reeperbahn). He doesn't do that alone but he has a business partner who seems to do most of the business stuff.
He has a rich history of being a gay rights activist, member of the Green Party (and ran for a seat in parliament for them), and artist (actor, cabaret). He even wrote a song that was later played by the legendary band Ton Steine Scherben/Rio Reiser. He is a St.Pauli support for decades as well, though not from the "active" supporters scene.
Even his harshest critics would not deny that he is the most successful president of the last decades. He played an important role in preventing a further downfall after relegation to the 3rd league, played a key role in keeping the club alive in the third league and started to build a new stadium - and not just some kind of stadium, but in a way that really fits to the club (size, rebuilding one stand after the other etc.).
The problem is that he is egocentric, does not accept other people's advice (except maybe for Markus Schulz) , is unable/unwilling to communicate properly with supporters, club members, club officials etc. and thus makes unnecessary mistakes and spoils big parts of his success.