Hi @alauer,
Here’s our answers. Please note that if you contact us here you will get a faster answer ??
1) Take a look at this article, please: https://help.shortpixel.com/article/34-where-is-the-backup-folder-located
2) Yes, you can do that. Just upload it in the same place and that’s it, the plugin will recognize the backups.
3) Yes. Before deactivating the plugin, you will see a popup asking you to save your settings or not, in case you want to activate it later. More information: https://help.shortpixel.com/article/66-what-happens-if-i-stop-using-the-optimize-images-feature
4) We can’t be sure. We would need to further investigate this, so we will appreciate if you can contact us here ??
5) Running the bulk optimization will only optimize those pictures that have not been optimized yet. Therefore the folder is not needed. However, if you want to re-optimize them using another optimization method (Glossy, Lossy or Lossless), you will need the folder.
Have a good day,