Is he a nice guy?

Probably a jerk. Seems like he would be.

I don't know if he's arrogant. he's got this goofy yet very very sarcastic sense of humor which cracks me up in like every movie he is in - like zombieland? yes. i bet he's so fun to hang out with, as long as you're not overly sensitive about things not being totally P.C.

He's a stoner. Has any stoner ever been a dick? Ever?

i met Woody twice in Ireland!
most definitely a stoner and the nicest guy ever!

Met Mr Harrelson personally at the Zurich Film Festival as a normal visitor. He is friendly, modest, polite and has a good humor. He took enough for his fans ignoring that the organizers were pushing a bit. Very glad that I was able to speak to him and get a selfie.

A friend of mine worked with him on Three Billboards and had nothing but great things to say about him.