Ok, I'll share soon. Honestly don't expect too much, no auto-fill at all - I might look at that in the future. It's what you call GUI scripting (using AppleScript) so it's only actions you can do manually with your mouse and keyboard anyway (except it's performed super fast). It's not "smart" and nothing feeds back into Alfred. I suppose I could generate a list of folders and feed that back... but I'm not sure I want to put too much effort into what will always be a hacky solution.
If I'm going to do it "right" I'd want to do it fully right. The main reason for this workflow was to bookmark a Firefox page into Safari. I really don't want to have bookmarks spread across different browsers. If you're in Firefox the script does a bit more you see... it copies the URL, opens Safari, loads URL, stops the page load, bookmarks into folder, closes safari tab and then returns to Firefox.
Using this workflow in Safari alone is useful... but not all that much faster than cmd+d and some mouse clicks. If you're a fast typist though - anything through text command is generally better I guess. It's a bit easier to create folders I guess too.