I read your post at least 6 times and decided that I didn't want to answer, mainly because the question itself has all the trademarks of a time sink. But since nobody else seem to bother so ill give you nudge on the way. I could go on and on about you are going about this the wrong way. Suffice to say most people would do this first before they did 100 animations that may all end up in the junk pile. In short one could say your screwed, altough you probably aren't it is a bit premature to say without knowing the facts.
You don't really want to do what your asking, it somehow falls into category of things that's almost there (in same sort misguided way some people refer the web browser as Internet, granted much more subtly). What you want is to transfer a clip. Its not so much that you couldn't do what your asking, let me be clear you can. However it would defeat the purpose of having the set in first place.
Ok so what is a set? Its a arbitrary container, it can contain anything. Elementary the set is not the application itself its the means for a application, it works as platform for applying things. Now a character set is a specialized set that contains the channels used for animation (channels again don't exist at all being just attributes marked for keying).
Now the character set is used as a kind of switchboard to connect the clips to your animation, as long as a switchboard of identical(or bigger) physical slot configuration slot exists you can drop the animation into this. However having a switchboard doesn't help since you only have the other half formed. The switchboard itself does no good unless its connected in some sane way. Likewise importing a existing switchboard does you no favors because the imported switchboard is not connected out to anything particular. Since a set is purely virtual it does not exist without the connections so it would be empty on import.
So to be of any bigger use the switchboard must be in place before you start wiring. Likewise the character sets would preferably need to be in place before you start animating. Then because you always load the model with the same set you would have no bigger problems dropping data into it. See the manual for trax, and clips tough you can and often do use sets for other things than trax animation (mov export inport being on other way).
It is possible to retrofit a switching board, its usually not very nice tough as most likely its as much work as doing the job right in the first place. So to get much use fo switching board may mean you need to redo all the wiring, or at least make substantial changes. Just like the analogy its possible to recreate character set, it may be slightly simpler because creating a set is simpler than doing physical wiring. How hard it is depends on many things such as whether the characters in each separate file have the same ordering or not, being same topography or not and so on... it is also possible its downright impossible because the slots just differ too greatly. (its not so much about having slots to drop data into but having the slots do similar things).
Now if you are in luck all your animations have the same character totally unmodified, in which case just ask for the character to be created with same settings as in other scenes, with same selections etc. Would create the same character set. Now this is now compatible with any of the other clips you have.
Now how to share with others, well presumably you'd need a production pipe that's shared with the others. That means that theres somebody in the organization of others who is responsible for deciding whet where and how, he would also be in charge of setting this up to you. As it don't magically appear, it needs to be engineered to be there.
Sysadmins, tds and so on all do jobs that when executed in best possible way makes you think they aren't needed. Yet you rarely see animators on 24 hour call. But you do see some of the tech guys, you usually don't notice them until things go horribly wrong.
