Hi sebwin,
that’s puzzling, I’m not sure where you encountered these limitations; I just tested variable names, there are no limitations. You can use any number of characters you want, they can include any kind of symbols (with exception of whitespaces, which are replaced automatically by underscores), you can even use Greek letters in an LaTeX-stlye (e.g., if you type \Alpha + \Omega, it will appear as greek symobls). Could you point us to the situation in which the system restricted you?
Cheers,
Timo