Mozilla Connect

Or a "lock folders" option. That would be cool. Option off, drag folders all you like. Option on, folders undragable. Btw, I'm assuming you're talking about Thunderbird here? Or do you mean the folders from your Firefox bookmarks?

Just use Filezilla. Regular ftp is almost dead or at least it should be.

Can't you just download them? There should be a download button somewhere I think...

Firefox doesn't support progressive web apps so why are you using Firefox for this at all?

I'd prefer a way to disable it per tab though. Sometimes I just need a tab to stay alive in the background