ak74u with rapid-fire
You go to "Create A Class" Then Primary or Secondary weapons to choose your weapon then after u edit your weapon.
go to create a class once you are a high enough level equip it as your secondary weapon
The AK-47 should be your first pick.
fails the level :P
you can get it at campaign or unlock it on multiplayer
Yes. Many classes of different weapon's, perks, and equipment.
Scavenger Or Scavenger Pro
This is more of an opinion question, but the assault rifles seem vastly superior in Call of Duty: Black Ops. I recommend the AK-47 with extended mags.
It was your weapon!
There is no best weapon in Call of Duty, it's all about your personal preference, if you like a weapon use it. If you don't like it, don't use it:)
You can buy things in Create a class and playercard.
the class you get after i believe reaching prestige 14. its the 10th custom class you get