Just to note, although a bad FPS might not be a server issue, is is a Blizzard issue, as I have a beast of a machine, and when in cities or crowded areas I drop below 15 FPS. I can run UT3, TF2, and almost any other First Person Shooter on high settings with a framerate of over 30. This is a design issue that seems to stem from the high data rates of the citys(people coming in view, out of view, and lots of things happening). This may not be lag, but it is an issue with the client server relationship, but it is likely poor coding on the client side.
In the city, if you experience people popping up out of nowhere - That is a bandwidth issue. One that no one has managed to solve yet. Its mostly an issue with the fact that cables that run into apartments are often very, very old. I had to tune my 20mbit down yesterday because it would periodically drop the connection, because the cables simply can't take it.
WoW runs fluid to semi-fluid on 4 year old machines with AGP slots at a net cafe I used to work at. I'd say thats pretty good, performance wise. WoW is one of the lowest req modern games out there.
As for Pentium 4 dual-core: I'm pretty sure they exist, I believe we have 4 of them in the office here, and no I don't mean Hyperthreading. Although it is possible they are just the Core-duos, I'm just pretty sure they aren't.
I'm not sure you're correct. The first dual core intel processor was the Pentium D, which isn't a P4 processor at all. Wikipedia seems to support this.
The CD Key is what you purchased. It's your proof of purchase, as well as your key to the game. If you don't have that, your CD is worthless, and Blizzard won't acknowledge your purchase without it. If you don't have the key, you don't have WoW.
They trust you not to steal from them, or didn't think the investment into a CD Key system was appropriate for their game. Just because there is no CD Key on some games doesn't mean you own the rights to distribute that game.
You got it. You can make one backup copy for your own records, but you can't make copies and give them to your friends. You'll never have that right unless it's explicitly granted to you by the rights holder.
There is no difference. One is simply an active protection while the other is working on the honor system. You still have no rights to the game data in either case.