@madonta. Thanks for using my module. Now, to answer your questions:
1. Yes, this is possible. You need to prepare a file to process the files for download, and then edit the helper.php file (somewhere around line 193, where the link anchor is added). See this site for more information.
2. I would love to show Turkish characters. I had a similar problem reported to me about Swedish characters. I asked the person to try the following, and he said that it didn’t work, but maybe you can do it. Where ever you see: you should see:
$rows[$i]
I want you to change that to:
JText::_($rows[$i])
Let me know if it works. If it works, I’ll add this to the next releases of the module and plugin.