Answers:
1. When you build your game you can change your skybank.
2. You download them,unzip them (if necessary) and place them in the proper folders...i.e. entities go in the entitybank folder,etc.
Most downloads include instructions.
3. Extra Debug 0,0,0 is a nondescriptive error message.
Get all of the info you can on what is going wrong and post it in the Bug Reports forum.
4. You will have to animate the model yourself to get it to sit.
A possible solution would be to put the good Colonel behind the desk and use the page down button to lower him so he looks like he is sitting if you aren't planning on having him react as in shoot at you...if so that's another story.
5. Items such as the binoculars and torch are pickups only.
You can pick them up by the have no fuction unless you use them as a key or objective.
If you get creative you can make them function but it requires a bit of scripting,a hud or two,etc.
6. See #5.
If you ask questions someone will answer them.
Unless it has been 24 hours or your post has been pushed down to the next page please don't bump the thread.
Thanks and welcome to the TGC forums.