Lambach
Arcane
He's certainly far afield from the usual cold malevolent nihilism of NE. The characteristic feature of NE is Death
Pretty sure Death is as plain Neutral as it gets. The embodiment of death in that Universe is Pharasma, a True Neutral Diety.
The embodiment of Neutral Evil are Daemons who represent not Death in itself, but intentional destruction of all life and Creation itself.
Now, while Daeran obviously isn't anywhere near that level, he operates in a similar way, i.e. he intentionally destroys others (usually not physically, but emotionally, financially, etc.) just for the sake of it and for his own amusement and he doesn't care at all how much damage he causes to others along the way.
He's the life of too many parties, not the death.
Urgathoa is the Goddess of both the Undead and revelry, debauchery and hedonism as well. She is Neutral Evil. I myself never figured out what the connection is between the two and how they can both be parts of the same Deity's portfolio, but that's apparently how it works on Golarion.
He gives people (mostly the other dudes) shit because that's what male members of the animal kingdom normally do to one another.
That's what you see while traveling with him. But according to his own stories and what others say about him, he doesn't just "give people shit", he goes out of his way to torment them in one way or another, with no provocation or reason beyond his amusement and/or spite.
I think the writers made him NE (and Delterius's hate is burning unusually strong here) because he's a rich kid and a lot of people's instinctive disgust instincts have been re-directed into the that narrow window.
Well, that, or because he's a sadist with a complete disregard for human (and other sentient) life. Being rich only makes him able to get away with it, instead of getting beaten to death by an angry mob.