You have to delete the set realm and patch file text in the main folder
You can't. If you don't have the current patch downloaded you can't play.
Start your WoW game like normal and Blizzard downloader should automatically start downloading the Latest patch.
No, you will have the same download speeds. It all depends on the quality of the server(s) you're downloading from.
If this is happening just recently ( in the last week or so from Monday March 15, 2010) then it is the Blizzard Background Downloader downloading chunks of the new patch they are going to release soon. This is normal, they normally release parts of it to the clients weeks before it goes live so save downloading time on patch day.
just delete that patch in your wow client folder
Right click wow symbol and choose "Run as Administrator" That usually fixes those kinds of problems
A patch mirror in WoW is a common element for that whenever a new patch is released for the game, it can be downloaded from different sources. One popular place for the patch is DepositFiles.
Yes it is.
Cataclysm Patch.
It's not really a choice to stop the patch as without it the game simply will not work, and it can't be removed afterwards without installing the game. The only way you could stop it is by using your firewall to block the downloader or manually stop the download every time, but your launcher will not allow you to start the game anymore until the patch is applied.
You can just delete the patch file once downloaded and installed by wow. You can not revert wow to a previous version because wow is auto-updating. Every client has the exact same version (for their OS).
Use the wow-launcher? It auto-patches the game and it starts automatically.