Just downloaded, 1st issue is that GUI button to turn on combat doesn't work. Testing now PlayDead, I'll give you some feedback on it later. Can you check this God's Whip I was talking about earlier? It happens after mob dies from 1st strikes or by spell which isn't instacast or flies slowly (Earthen Grip / Freezing Arrow).
Another thing might be adding to buff items stats food (those INT, AGI, MAX MANA, MAX HP).
[EDIT]
After little testing I see one thing that might issue (at least for me). When it's regenerating by food or potions, it's waiting until my mana % >= min. mana. It's waiting standing still doing nothing. It might work for regenerating hp. But when it used soup to regenerate it might attack as well. However if it would attack while using soups and pots Play Flute would to be on same min% as play dead.
[EDIT#2]
Another suggestion, can you consider using Play Dead to regenerate HP just like you did with mana?