Finally finishing everything on my CDLC, I now want to add DD, however I need phrases to do so. Can someone recommend an easy way to do this? They way I do messes up the difficulties in the song, where if you lower the difficulty setting, it brings entire parts down to a minimum.

Depending on the song, it may not be that quick and easy to add DD manually. Ideally you want to define the phrases so that each phrase is an identical or similar small part of the song (ie. a particular riff). If you wanted to try DDC, you just have to place section markers and it will try to find matching note patterns and place phrases automatically.