Hi,
thanks for your response about the documentation in the hover panels. I really put a lot of time into the documentations, try to keep them up to date... I'm sorry, that there are some misspellings and that I'm not a native speaker, so the wording might sometimes be wrong.
You are correct, that the Visforms installation creates a Visforms folder in the Joomla! Media image directory. Visforms itself uses this folder (by creating a subfolder) as a backup folder for uploaded files on some special occations, so usually when you start it is empty. You could use this folder, but a backdrop is, that Visfoorms will also delete this folder, when you unistall Visforms.
Many components leave residue, when you uninstall them. Visforms does not. If you uninstall Visforms it will be removed completely (all folder it has created during the installation, all Visforms related tables in the database). This is, because every Visforms installation package also works as update, so the only reason, why you would have to uninstall Visforms is, that you really do no longer want to use it and in this case (that is my opion) it is correct to remove everything completely.
It is always good to know, which feature Visforms users are missing. I think, that having control over the uploaded file name, is actually an interesting feature. I will put it on the feature request list, but I cannot promise 100% that I will implement something like that or when. But I will take a look into it.
Regards,
Aicha