cant be bothered to write anything extremely detailed, but...
1. you can pvp other classes in your own faction by offering a duel. that person acceps or declines. if you move start to fight and move out of the nearby area you automatically lose. battlegrounds are nice too.
2. i've only played eq2 a bit, so i can't go much in depth. however, like eq wow is very item dependant. there's tons of stuff to do from lvl1 to 60, but at 60 the game changes quite a bit. if you want some of the really high-end loot you're either going to have to join a raiding guild, or grind the battlegrounds (you earn reputation with a faction associated with the battleground, and at various levels of reputation you can purchase increasingly good stuff, which in some cases is comparable to the 40-man raiding loot).
3. the thing in wow is that items are typically "bind on pickup" or "bind on equip". BoP are usually items that drop off bosses, or that you get as quest rewards. When you pick up these they're bound to your character, meaning no one else will be able to equip it. you can either wear it, put it in the bank, or sell it to a vendor. BoE items normally drop from "world mobs", and can be worn (in which case it'll be bound to your character), sold to a vendor, traded to a player, or sold at the auction house. the ah can be a great way to make an income, if you learn what's in the demand, how much something is "really" worth, and spending enough time farming for it, or doing the buy low / sell high strategy. in other words, no twinking.
4. very hard to say what you put into 'fun', but with millions of subscribers i guess a lot of people think it's fun - i know i do

however, at this point everquest does have more end-game content, and some that level up to 60 find the game gets boring. blizzard is pumping out almost monthly content patches though, so it's a pretty interesting world to explore and play in.
i personally fought Ragnaros (second hardest boss in the game) with my guild for the first time yesterday, and even though we got steamrolled it was a blast from start to finish.
so give wow a try
