Yes they are against the policies of Blizzard. Further more, they could also be considered illegal law-wise. They could be considered stolen property.
Yes, they are very legal, just Blizzard does not like them, because they take their money.
They are against the ToU, and will get your account banned. Plus blizzard can take legal action against you.
There are no GM power hacks on retail (legal) servers. There might be on private servers, but private servers are illegal. We can not help you with that here.
All private servers are "legal" in that they are not breaking any laws. However, Blizzard considers private servers a violation of the Terms of Service of World of Warcraft in general, and therefore, any private servers are actually in violation of Blizzard Entertainment's Terms of Acceptable Use for their software. In other words, private servers are like pirated software, and you should always be careful to be sure your username and password on a Private server NEVER matches any other username/password combination you have elsewhere online.
World of Warcraft cannot be played offline - it's an online game that requires server access to run. With regards to downtime, the realms are offline on Tuesdays (US) or Wednesdays (EU) for scheduled maintenance.
Private severs violate the Terms of Use for WoW please reread them here http://www.worldofwarcraft.com/legal/termsofuse.html because it is clear that you do not have a full comprehension of them
There is no legal way to get "free" authentication keys for World of Warcraft. You must purchase the discs or use the blizzard store to purchase one.
If someone gives you a licence key to World of Warcraft, you have to ask yourself: who gave it to me, is this a legal key? if it is, then input the code and you're done.
You can not play World of Warcraft for free with out downloading it. WoW is a client-server game, you have to have the client installed in order to play. While there are free private servers available, they are not legal, and are usually pretty buggy.
There is no website for a free legal world of warcraft. You can play the free trial for free though, and there is no time limit on it, however you can only level to level 20. The link is below in the related links section.
Most World of Warcraft guides ARE legal, depending on what it is they are telling you what to do. If they are showing you how to make a bot to play the game for you, then you probably should not use it.
No. It is completely impossible to hit level 70 from level 1 in one kill on a legal server. If you see someone do this, it is either a GM (Game Master), or you are on a private server (illegal by the way).