I agree that the tutorial should cover all the Up/Down/Forward modifiers on attacks, and even multiple presses of D. I've noticed many people reviewing on NG who are angry that they can't jump or bored because they think combat is only "spam A then press D before you get hurt." However, I believe that finding out the abilities of enemies should be part of the game. Players should be able to figure out their own tactics against them rather than being shown them right away.
I definitely agree that Vandheer should drop health, like the tank boss on NG does.
Some might argue that the game is too easy already with health drops and normal difficulty enemies. If there's an easy mode added, there should also be a harder mode added (so Easy, Normal, and Hard/Futile). This would make every enemy have the ability to block/dodge, and could remove the health drops too. These separate difficulties, if added, should get their own scoreboards, if that's possible.