Nettletooth Djinn + Mind Harness triggers

Quote:

Originally Posted by BirdsOfParadise

It is my upkeep. I am controlling my opponent's Nettletooth Djinn because I cast Mind Harness on it on a previous turn. This upkeep, I intend not to pay the cumulative upkeep cost.

At the beginning of the upkeep, two triggers go on the stack, one from the Djinn and one from the Harness.

Question 1: In which order do those two triggers go on the stack? Do I have the power to choose? (I know about the APNAP rule, but I don't know whether it applies to ownership or to control.)

This one is definitely yes, you control both triggers, so you choose how they get put on the stack. APNAP only pertains if you didn't control both triggers, but you do.

Quote:

Originally Posted by BirdsOfParadise

Question 2: If the Djinn's damage trigger is put on the stack first (either because it must or as a result of my choice), then the Harness trigger resolves first. I choose to let the Harness be sacrificed. My opponent regains control of the Djinn. Who takes damage from the Djinn's trigger, me or my opponent? (That is, does the game interpret "you" as "the controller of Nettletooth Djinn" when the trigger is put on the stack or when the trigger resolves?)

I'm fairly sure that you will take the damage, because you control the trigger and the trigger is already on the stack and it says "you" (i.e. the controller of the trigger). The only thing that "changes" here is that Nettletooth is no longer controlled by you, but that only matters if, say, you have something like Energy Field that cares about who control a source of damage. If Nettletooth said "deals one damage to it's controller" than, I think, it would work the way you describe, since then when the trigger resolved, it would check to see who controls it. As written, once that trigger is on the stack the "you" is set as the controller of the trigger, control of the Djinn is incidental at that point.