Sorta burned out from working, so I didn't really catch up much on this topic (or keeping up with it for that matter).
Nice is good in moderation. I mean, not that I condone it too much, but it's good to spoil oneself every once in awhile (meaning loosen up on the morality front, and have fun getting wasted once in awhile, or be a little more adventurous on the dating front and etc.). Sometimes, just to feel human, and not like a tool, it doesn't hurt to be an ass(hole) every once in awhile. How I see it, or more how I prefer to go by it, if you want to be a jackass for any reason, take responsibility for your actions one way or another.
If you're messing around with someone, and it may come off as a form of bullying to them, or third parties, let the victim in on it, at least; or buy them a beer to make up for it. I mean, as long as you let them know you were trying to have fun with them, and wanted them to lighten up (especially if they were already miserable when you were doing so), then you get the best of both worlds; you are an asshole for a moment, and you're doing good by taking responsibility for it. Make it a habit (being more assholeish), however, or don't take complete responsibility, and it'll border on the notion of "Someone who is nice to you, but not the waiter, is not a nice person.".
That's my thoughts on the moderation of the Nice Guy:Asshole ratio. Keep it balanced enough to be human, but a good person while at it, but also
enough to have fun as well at someone else's expense. I guess a good way to work with it is be child-like in your manners, but be an adult about it as well.