Yeah Mark, the eight skill thing is probably the weirdest but best part of Guild Wars, espically in PvP. It seems really limiting and less strategy-like when you look at WoW which has tons of skills and item ability's flying around all the time, but I'd say its more strategic, because if you fight say...a Warlock in WoW's PvP, you can pretty much guess what he's going to do pretty quickly because all Warlocks have access to the same skills, it pretty much just becomes an issue of "is he Destruction, Demonology, or Affliction..." overall. But in Guild Wars, with 100+ skills for the Necromancer and 100+ skills for whatever his secondary is, there is a ton of possibility's on what that Necro could be. He could be degen, life steal (ignores most Monk protection spells), minion master, hexmancer, etc. And even in those different subtypes there is many different builds for each of them.
That isn't to say you won't find a lot of people running the same build though, you will find people who run "cookie-cutter" builds, just like you find people in WoW running the same talent builds because they are optimal builds that win a lot.
Also if you got Prophecies, it would take maybe 30 hours to get to Level 20, but even then you won't (generally, you could get lucky) have max stat equipment either. Factions is quicker, NF is a bit longer than Factions but shorter than Prophecies, however I always recommend Prophecies since it basically teaches you the entire game (even the PvP modes) in a decent story mode. Its also the only campaign that will give you skills for quests, so its cheaper to be PvP ready as well.