No
no it is good
You cannot sky jump in mw3 only in Bo2 Campaign.
by completing the campaign
Yuri and Makarov
yes
there is no cheat for online multiplayer games. The only way you can "cheat" is by using hacks. If you want these hacks look on google or youtube and search for "Mw3 Hacks for wii" Or something like that.
There are around twenty cheat codes for the Call of Duty MW3 game for the Xbox. Some of the cheat codes are the secret killstreak, gold camo, and easy XP.
There are no actual cheat-codes, only easter eggs.
Nope, you'll have to tough this one out by yourself.
Their are no cheats yet. You can only get perks so far.
you probably need to use some cheat/hacks
There are no cheat codes for MW3 on live. What you are asking for are hacks and mods which are illegal and result in being banned and profile whipped clean of gamer score.