The current version of Luxinate (ver7) is kind of spotty when it comes to handling the LuxPlaylist and LuxUser options.
Due to recent updates to youtube-dl, there are now options in youtube-dl that can help Luxinate handle these kinds of requests much easier.
I've been working on Luxinate v8 for a little while now; this new version should handle many of the recent issues.
Since v8 relies mainly on the new version of The Alfred Bundler (which is currently in development) to handle utilities and icons, Luxinate v8 should be much cleaner and run much smoother than the previous versions of Luxinate.
Until I can release Luxinate v8, the LuxUser option may be failing due to the recent options added to youtube-dl.
The best way to download these videos now would be to run youtube-dl from the command line.
cd /Users/mattkneale/Desktop/YouTube\ downloads/;/Users/mattkneale/Library/Application\ Support/Alfred\ 2/Alfred.alfredpreferences/workflows/user.workflow.ACFE790C-B8A8-48DB-972D-3A57969BFB51/Resources/youtube-dl https://www.youtube.com/user/ernell42
You can try running the above command into Terminal.app for a makeshift way to download the user's videos to your download's folder, although, this isn't guaranteed to work.
Personally, I haven't really used Hazel, and I'm not sure how you'd achieve what you want to achieve. I'm sure it could be done if Hazel can trigger shell scripts based on watch folders. Sorry I can't be more specific at this point. Hope you can make sense of the TinyPNG API requests in the tinypng.sh script -- that's the stuff you'll need to run from the Watch Folder trigger.
