I'm afraid that the answers to your questions Redking are mostly in the negative:-
No
Yes
No
I have lots of other projects at the moment, so a "Riderless Camel" will have to wait for these to be finished first.
Here is a link to a 'cut-'n-paste' tutorial....
http://forums.civfanatics.com/showthread.php?threadid=29026
And I have no idea how "Supply Wagons" could be made to work in the game, except as a substitute for Settlers.
In a scenario they might have a use.....Napoleon's invasion of Russia for example could use suppy wagon animations for King graphics, or workers could be renamed and have a supply wagon as part of their animation (so visually you would see a 'line' of these behind Napoleon's army as new roads and terrain improvements are built in the newly captured territories).....
....but that's about all I can think of.
Later Edit: More thoughts....
If the AI understood what land transport was all about, then wagons could be used to carry slow moving foot units....but this is not possible at the moment.
Or
if we could give these wagons the "Radar Tower's" attack & defence bonuses, then armies with supply wagons would fight better than those armies without them, and so would be a vitally important unit (as indeed they were in reality).....but this is also not possible at the moment.