A player can't use Creeper Plant to deal 1 damage to a dark player, right? I assume Light and Dark are just sub-types of players, whereas the cards that refer to Dark are using it as the term for the card type, I.E. Heartless / Villians.

i do believe that is correct

Q: Do Magic Cards and Dumbo effect Dark/Players?
A: No

Same concept.

thats what i thought