There are other characters that Limewire cannot accept from a Mac: [] for example. The m-dash — apparently is one of them. There are share/freeware programs at versiontracker that can batch rename files if you wish to make a concession to Limewire's idiosyncratic nature.

Chat is a very iffy thing on Limewire, and the chat connection can break quite quickly. There is no warning; the other person simply fails to respond. They in fact do not see what you have written.