My point is that RP is in the eyes of the player. Saying that it's not RP to describe it the way I did puts too many rules on it to make it worth worrying about. I've already stated I'd never last in a strict, filled with stupid rules RP environment. I'd quit before I got started. I don't like being "told" how to play a game and I guess that's where the RP thing falls apart on me. I guess I'm stubborn or something. I don't mind people RPing, I've tried D&D and enjoyed the game but I do admit I was the worst "RPer" of the group.
There is only one rule though to good roleplaying: Have fun.
Actually, what I am trying to explain, starting with the examples I pointed out in your statement is that roleplaying is more than making a character and advancing it. It is, quite simply, taking on the role of a character in a fantasy world. It goes beyond why you kill stuff or advance your skills and more into why you associate with the people you do, your character's personality, strengths and weaknesses, your character's background and family. Roleplaying is imagining that your character really does exist as a thinking, feeling person and attempting to portray your character and his or her action's in step with this portrayal.
One good example from Sukaisi: Because she is a Vah Shir, she refuses to attack or kill feline mobs. Even if it limits XP opportunities or makes certain quests impossible, she tries to ensure that she does not participate in the slaughter of creatures so much like herself.
Another example would be refusing to raid the Plane of Growth as a follower of Tunare (I hope that is the right deity). Unless there were a way in-game to renounce your character's beliefs, attacking your own god simply for the phat lewtz is antithetical to roleplaying.
These aren't really rules per se, roleplaying doesn't really have any rules. The main guideline is that you play a character your enjoy and you try to be consistent in the presentation and development of your character. If other people can imagine your character as a real person and doing the things they are doing because they make sense from a realistic point of view, then you are roleplaying.
I hope that helps to some extent. As a gamemaster of a lot of years, I have had to explain this to a lot of people and try to get them to understand what roleplaying is all about.