#control-changing effects

Theft question: If I use a theft spell like "Threaten" or "Price of Loyalty" that let me have control of a creature until the end of the turn. Then I cast Slip Out the Back. Since this phases out until my next turn, and I am still the controller when the end-of-turn effect hits, do I keep this creature permanently?

This happened to me and enough people disagreed with me I let it happen, since I didn't understand the ability well enough to know, myself. If a opponent casts Act of Treason on my Kotose, the Silent Spider, can they then cast the card I previously exiled with her triggered ability?

If someone casts Treachery on my Elesh Norn, Mother of Machines, do they untap 0 lands or 10?

Hello! We are in a game of commander. A creature has vapor snare attached to it. Someone goes to take control of this creature with memnarch’s activated abilities. How does this resolve? Does the enchantment stay attached and return to the vapor snare owner or does the enchantment lose relevance? Thanks in advance!

If I use a card like Control Magic, to steal a creature that was cast with suspend, can it attack/activate tap abilities? TLDR does it still have haste?

Rules question: Exert. How long does it stay on the creature if I am not the controller of it? Example: I steal an Exert creature and attack with it. It's now exerted by me and when it returns to my opponent it does untap because it was not exerted by him. Then in his turn he make it tapped. But in his turn I use a permanent control effect. Now my turn again, there is the tricky part: will it untap or is it still exerted by me? And what if I steal it a few turns later?

If I cast Frenzied Fugue on my opponent's creature, then destroy fugue during my turn while I have control of the creature, does my opponent still get the creature back at end of turn since the source of that trigger is no longer on the battlefield?