Run away, run away.
I created a sample for the Flextras DataSorter for editing YouTube Playlists. It was a nightmare. None of the API documentation was any good and the XML packets you had to send[and the ones you got back] were nothing worth documenting.
There are throttling limits, so for big updates you need to add an artifical delay or else you'll get a bunch of errors.
This is the app:
Source code for everything but the DataSorter component should be available. ( https://www.flextras.com/DataSorter/Samples/YouTubeSample/srcview/index.html ).
Look at the com.flextras.samples.youTube.view.PlayListDisplay.mxml component. It looks like I documented it a lot. Let me know if you can take the code and turn into a reusable library.