As far as the server goes it is very quiet, however, we are a guild of around 400 (including peoples alts), so there is always someone around from the guild.
As we are mainly a social guild we cover all aspects of the game, the only exception being PvP, but that is only because we have very few players who want to PvP. We have 2 10 man raid teams who are both currently recruiting as we recently lost a few players to RL etc.
PCG is open to everyone and for the majority we are a mature guild. We have our silly moments but we have a well ordered guild. People are always willing to help each other and ask for help in guild chat. As I said, we are a large guild which means we always have people online and also have a lot of people who know alot about various bits of WoW so there is normally someone around to answer a questions or help out on a quest etc.
Although we are on an RP server we don't take part in a lot of RP ourselves. We have the occassional guild events which can involve some light hearted RP. All we ask is that you respect anyone on the server who is partaking in RP as that is the nature of the server.
Hopefully that helps to answer some of your questions. If you want to know anything else just post on the forum and someone will be more than happy to help you out.