[Delphinus]

Can you post a picture of what his lips look like when you say they look sore?

Flukes is another possibility besides ich that can cause the twitchy head and scratching against rocks. When I had fish with flukes it was obvious that there were white spots along the body and eyes. Just like Daniella with her CBB though, you with your mostly white butterfly might have a very difficult time with a positive confirmation that there are flukes or not. From all that I know about flukes though is that certain fish, and unfortunately butterflies and angels are apparently very prone to these, it's a safer bet that they've come in with them than they've come in without them. You may wish to consider a treatment with Prazipro if his condition doesn't improve soon.