1, Is there a monthly fee to play?
2, Do you have to level your character, if so, how easy/hard is it?
3, In WoW, Player Vs Player was a huge part in my play time, what is it like in this game?
4, What is the actual end goal of the game? (if there is one)
This is an answer coming from a seasoned 2 year veteran.
1) No, there is no fee to pay. All of the campaigns out right now are standalone games. You could buy any of the three and be able to play it all by itself, but having all 3 combined on your account is much much better for many reasons.
2) Levelling your character is not an issue, your character is capped at level 20 and can easily be done within a day (hardcore or not). Everything is dead even. It is very easy to get the best possible armor and weapons. In fact, if you don't care how they look, you can get the best performing weapons and armor for free just for trading in monster trophies to NPCs called Collectors.
3) Guild wars has a good PvE feel to it, but this game was built around pvp. everyone is completely balanced and even, so it's player skills, not time spent grinding that decides a victor. It's very strategic, and there are different types of pvp. If you want to skip the Pve portion of the game, you can instantly make 20th level pvp characters that can only participate in pvp activities, and cannot visit pve towns, but playing in pve will unlock items and modifications and skills used for your pvp-only characters. However, playing in pvp will reward your kills with what is called Balthazar Faction, which are points that can be spend to unlock skills and items without having to play in PvE.
Additionally, on pvp-only characters, you are automatically set up with maximum defence armor and maximum damage weapons.
4) This is unlike other MMORPGs, in fact, Guild wars isnt even an MMORPG. People do not play in 1 big seamless world. Going out and killing monsters or doing quest in missions is all instance based. You get your own copy of the map all by yourself, and with the rest of your party. Towns, cities, and outposts are where you mingle with people to form groups. If you cannot find other people to play with, you can hire (for free) automated henchmen to fight for you, which are surprisingly intelligent considering they are just AI. If you decide to buy guild wars Nightfall, you can get Heroes, which are essentially henchmen, but you can outfit your heroes with whatever you want. Any weapon you want, any armor, any skills, any attributes. They are basically henchmen that you create yourself, but you don't get to choose how they look. You can give them commands by setting up flags.
Back to what I was saying about this not being an MMORPG, it is actually just an online RPG, it is not MM. What I mean by that is, this is more like a console game, like final fantasy, but online. it has a real storyline, cinematics, lots of dialogue. When you beat the game (with the exception of the original guild wars, guild wars prophecies) you get a special powerful endgame item with perfect mods and low requirements. Getting to level 20 is basically a tutorial, it's all easy up until that point, and beating the game for a beginner would only take a few weeks or maybe a couple of months depending on how much you play.
The real part of guild wars that makes it addictive is getting the best looking items, the best looking armor, lots of money, displayable titles that are acquired by completing great tasks. It's all about status symbols.
This WILL seem very different from WoW, and you likely won't enjoy it at first because it seems so strange and different, but it grows on you in time and you really start to respect the balance of it. There are no hacks, no cheats. There are a couple of farming bots around but they don't bother you. There are very little bugs, very little lag.
You can get a free trial of all 3 campaigns on
www.guildwars.com or you can ask someone for one of their free trial cards. I probably have 3 cd-keys with trial periods.
Anyways, try it out, it's not for everyone, it's about SKILL, not hours spent grinding. A newbie player could be naturally better than a player who's been playing for a year. Normally people who lack skill tend to whine about the game cause they can't just stay up for 2 weeks all night every night grinding to get ahead of everyone so they complain that they lose and run to WoW.
Anyways, have a good one.