So to get back to the other questions on this thread, and to add some more:
I gave my current answer after each question, just so people can see how I resolved it in game and know my thoughts why.
1. Would Guise Borrowing Pride allow Guise to use Prejudice's power? If he borrowed Prejudice would Expat be able to use Pride's power to use Prejudice?
If so, does it work like above suggested:
Guise borrows Pride, Uses its power to deal 2 projectile damage, then activates Prejudice's power, causing Expatriette to deal 2 projectile damage?
Reversed would it work the same way (Expat uses pride to make Guise deal 2 projectile with Prejudice?
If Expat no longer has access to the card, does that cancel the interaction between the two guns?
A. It would work exactly as stated because the powers reference each other, and don't care who is triggering the power. The current wielder of Prejudice would deal the second shot of damage because using the power doesn't change the name on the card, only Lemme See that is doing that.
2. If Guise borrows a gun loaded with Shock Rounds and uses the power, does the Ammo go off, causing Expat to deal 1 damage to each non-hero target?
A. Yes, the ammo triggers off the usage of the gun power and doesn't card who is using the power.
3. How Does Guise-Adept work when Guise borrows an instrument but not his music?
A. Guise uses the power on the instrument, and can use songs in Adept's play area, because the powers refer to the card effects they can activate, it doesn't matter where those cards are.
4. How does copied text of a form card interact with Bestial Shift? If Guise is copying Naturalist (which is pretty much the best idea ever) and Naturalist plays Bestial shift while in Gazelle, uses the free power to shift to Croc, what does Guise do during this time?
A. When the Symbol enters play the text on a form card activates it, so both would activate the text. For this resolution Players choose to let Guise resolve the effects first:
1. Guise Causes the Naturalist to regain 3hp, then uses a power. Naturalist causes Naturalist to regain 3hp, uses a power to change to Croc Form.
2. Guise Causes the Naturalist to deal 1 target 3 toxic Damage, then Guise uses a power. Naturalist causes Naturalist to deal one target 3 damage then uses a power.
This would work this way because the "You" is referrant to the player activating the text, which is being done by two seperate heroes, so both would treat The Naturalist as The Naturalist, and "You" as their own player. The idea of "You" being the player activating the effect is from "I Can do that too" as it pointedly leaves out any covering of "You" being changed to Guise's player, presumably because the player using the power is "You."
5. If Naturalist or Guise use Nature Forms power does the other get to trigger the effects because it is symbol based?
A. This is different from the one-shot because the one shot puts the text into play, but with a power the text is in play, and we know that playing Nature Forms power doesn't let Naturalist use the text without activating the power. Both Guise and Naturalist have a copy of the power's text, and activate theirs when they use the power.
I understand the argument that playing a card is as personal as using a power, but using a power is activating the effect of the text, playing a one-shot is playing the text to the field. Anything can react to a card entering play, when they react to a power they react to a player using a power.