2. Forget, for your need Prethink is fine actually. But I'm still wondering if there is not a more appropriate way to do that instead applying a lot of times the glow when it needs only one time. You could use the provided ZP forward when player becomes zombie and back human, then applying glow at this time.
3. You have to do the checks before retrieving player's buttons and about the returns, it will just generate less code.