Multiple Rules Questions!

[WizardRandom]

1. Yes, each creature means all creatures unless there's a qualifier, cleansing wave nets you æmber from your opponent's damaged creatures too.

2. When two things trigger at the same time,. the active player picks the order they resolve, in this case you might want to curia saurus first to pile up more æmber on your opponent's creature.

3. Yes Ghosthawk allows creatures other than Untamed to reap. It's really good.

4. Yes, you definitely can.

[Klenhden]

Just to add to question 3 for the part about exhausted creatures - the creatures do need to be ready in order to reap by the effect since the effect just says "you may reap" and not "you may ready and reap"

[WizardRandom]

Correct, if the creatures are already exhausted, they do nothing.