Monster Hunter Rear:
"Attack: Clear a corpse from an opponent's Unit, then draw 2 cards."
If the enemy Unit does not have any corpses, can I use this Attack Power to just draw 2 cards?
No, you have to clear the corpse to get the card draw.
"Apply damage to a hero equal to the strength of its supporter/forerunner"
The applied damage is equal to the Strength of whose supporter/forerunner? Puppeteer's supporter/forerunner, or the damaged Hero's supporter/forerunner?
It's the strength of the forerunner or supporter of the hero being damaged. This will be 0 if that hero does not have a Supporter or Forerunner.
"Attack: remove 4 damage from a hero."
This says "remove 4 damage", not "remove up to 4 damage" (as in the case of the Priestess Vanguard from Pixel Tactics 1). Can the Divinity heal less than 4 damage with this ability?
I'd say no in this case. It needs to be exactly 4.
This ability doesn't have a loudspeaker icon, but I think it should.
"Ranged Attack. +1 Attack Strength for each corpse in your Vanguard."
The ability says "+1 Attack Strength for each corpse in your vanguard", but the icon shows a "+2" modifier. Is the bonus +1 or +2?
It's +2. This is a misprint.