You should be aware that not all kinds of URLs can be downloaded. First of all, the direct link that was generated by another file host will be tied to your computer, and hence not downloadable by the site. If you're trying to paste an URL of the file page rather than a direct link, it will be only downloadable in the case if this host is supported by Leech mod - XFileSharing will navigate through the hierarchy of pages and extract the direct link which is suitable for downloading.

1. The remote downloads are generally working, but the progress bar is frozen

You have to ensure that tmp/.htaccess is in effect for all of your file servers. Please check that you have mod_headers installed in Apache, and that the AllowOverride rules are giving it a chance to be in effect.

2. I'm getting a strange popup error right before finish

Please check that the Perl module named 'XML::Simple' is installed on all of your file servers.