@murgatroid99 For the Lukka question, does it matter that the ability actually says: Creature cards exiled this way gain "You may cast this card from exile as long as you control a Lukka planeswalker." aka, the effect is complete in granting the ability to the card, so it doesn't end when there's no more Lukka?

You're right, it does. I didn't read the ability carefully enough and I thought it was like Thief of Sanity or Hostage Taker