I listened to him on his Air America show mostly in the way I watch John Stewart.. it's always fun to watch someone get skewered for making stuff up. I respect the fact that he always had guests from both sides of the aisle on for interviews and gave them a chance to speak their piece. He detested O'Reilly's microphone bullying (cut him off, etc) and made it a point to allow people their voice. Obviously, if he disagreed with their position, there would be followup questions and commentary, but that was kind of his job.
Yes, Al is for gun control. That is not a secret. I assume that he didn't put it on his site as it is simply not an issue that ranks high with left wing voters. In other words, it would be seen as negative by the right and ignored by the left. (I admit I am making this up, I'd love to see the list of top 10 political issues that left wing voters are using to base their votes on, but my sense is that RKBA is simply off the radar)
I'd like to see more people like Al run. That is, I'd like to see people that aren't entrenched in the political bubble come in. The current crop of congress critters show very little away from "business as usual". Maybe it is just a wishful "take back the government and return it to the people" mentality I am taking on today though...