Yeah, I definitely agree with the XP system being both pros and cons. I do like how they limit features, but I can see new users down the line making spammy comments and whatnot in order to get XP quickly.
Exactly what I was thinking, also many people may feel cheated by the fact that they are unable to access the features of the website off the bat.
Yeah like the "You can only join x amount of tribes at this level." I can see how that may deter people who are interested in a lot of things, but would rather lurk. However, I also like that because it requires users to participate on the site in order to belong to more communities.