Hmmm... well, unless you're joking, labelling anyone a "typical artsy MacRob lefty who brands anyone who supports free-market principles as an 'evil capitalist'" does come across as a bit pretentious. I think pretension is mostly about how disrespectful you are towards other people and attempting to justify that through intimidation or showing off how clever you are (there's a fine line between standing up for what you believe and being downright preachy). Also, just an air of pompusness or a 'holier-than-though' attitude can come across as pretention. So, I would say, (from the posts you make on FSN, lol) that no, you generally aren't pretentious. I'm sure you probably have your moments though

Off topic (sort of), I tend to find contemporary plays quite pretentious. Although I've had a few bad experiences with people into theatre which could warp my view on things.