Well...at the very least...your ambition is admirable. Here's several answers that may help you
A guild is just a guild...it can be PvE and PvP. Guild battles are PvP though. On a little note though...if you're just starting guild wars, JOIN a guild first. For a new player, the costs of a guild hall itself can be demanding if not financially crushing. I'd join a guild first, so that you can see how it works.
I'm not quite sure what you mean by this, but I'll try to answer it. A PvP character can enter into PvP, but normally, at least in Guild battles, the character in question is using perfect weapon sets, as well as fully upgraded perfect armor. Again, an expensive proposition.
Guild wars does have a ranking system: the top 1000 guilds are listed. Bear in mind that there are 10's of 1000's of guilds, if not more. Getting onto the guild ladder, for most guilds at least, is a rather daunting task. It's the Guild Ladder on Guildwars.com
I couldn't tell you why the site is slow; it's ok for me.
New Player Need l337 advice.
Snow Bunny
Onarik Amrak
From the looks of things you're not experienced enough to be a Guild Leader.
Join an existing one.
Join an existing one.