you still have to access symbols within string using the prefix, and I imagined Arc's (use ...) doing the same.
Arc should register in some way that the module was loaded, since if two other modules do (use 'x), then they have to reference the same table. This is, afaik, what Python does. So 'locally' (within the current module), you access the symbol table of another package with the name you want (if you don't supply one, then it's the same as in the file), but the system remembers who is who globally.
Each source file is a module, yes.
To be able to load a list of modules, like
(map use '(string regex parser))
I think that it is important that the first parameter to the use function be a symbol, e.g. (use 'string) instead of (use string).
I like your suggestion (specially changing the names to avoid clashes)... Yes, it could be a nice way to avoid the prefix... ;)
