There is no way to obtain the Skylift helicopter. No cheats, no nothing.
I hope you mean Spec Ops. Simply fill out the criteria for 3 stars, or do the 3 stars difficulty.
You're not going to get any of that here. Go to the VG boards, and make yourself a topic asking to do that. I'm sure someone will help you.
Check your NAT type. If you got "Strict" then move your console closer to your modem. That's if you got wireless. If you're wired, check your cable.
I'm not sure what you mean.In multiplayer or something? As far as I know, there is no significance to a mark on a pipe in any game mode, on any level, online, or offline.
Unfortunately, you cannot have bots in Multiplayer. It's a Black Ops only thing as far as I know.
No. At that point you go back, find the intel, and do it on all difficulties.
No. You just play, and hope someone sends you a Boosting lobby invite. Or start your own.