1. Very probably. The code is somewhat hairy and the author proclaims it to be "alpha" quality.
2. Find the leak, write a patch, and submit it to the author. However, the author may not be actively maintaining the module as the last update was July 15, 2002. If the author is not maintaining, take it over!
3. I don't like lists with 2 elements, either. :-)

Update: After glancing through the source, try removing all references to Exporter in the code. That might be the problem. (Spreadsheet::ParseExcel doesn't actually use any Exporter functionality, from what I remember, though I could be wrong.)