not every one of them. If the developer accepts the mod it's legal (E.G. DoTa for Warcraft III: reign of chaos)
No, you cannot install mods on the 360. You need the ps3 or PC versions to install and use UT3 mods.
Google for Modstallation. You can use that software to install mods.
Check out the link below for a guide of how to install mods in Minecraft.
It might not be out yet but it should be. You have to download and install forge then you can install mods by going to .minecraft/mods and adding a mod there.
There are not really any mods that are allowed to alter character appearance in World of Warcraft. This is because it would involve altering the game files, which is against the rules.
The Server has to install the mods Not You.
You can't
loongkee
no
Easy
Just to let you know you can only get mods on the PC version