question 1 @ Borg.
It make no sense that you do not gain permanent control of an enchantment. How are you gonna reveal it then.
To answer question 1:
I believe you own the spell until end of game or your opponenet steals it with 'steal enchantment'.
That may be correct.
I looked up the card in the codex, unfortunately the two examples given are incantations.
No example with an enchantment. Though strictly reading it, it does indeed seem like you gain control of it until end of game or until it's destroyed but I'm not 100% sure.
Here's the codex text :
Reverse Magic
Current Text: "When this creature is targeted by an incantation or enchantment spell controlled by an opponent, you must reveal Reverse Magic during the Counter Spell Step. Redirect it back to the caster, who now becomes the target of the spell. You become the caster of that spell, and now control that spell, and may reselect any other choices the spell requires you to make. Recalculate the total mana cost of the spell; if the new cost is higher than the original cost, you must pay the difference. Then, destroy Reverse Magic."
If the spell has secondary targets you can choose new secondary targets. If a hidden enchantment is Reversed, the new controller of the enchantment may look at it. However, you may not look at it before deciding whether or not to pay the reveal cost of Reverse Magic. If you cannot or do not want to pay the difference after recalculating the mana cost, you may cancel the spell instead.
Example: A Warlock casts Dissolve on a Wizard, and selects the Wizard's Regrowth Belt (cost 6). The Wizard reveals Reverse Magic, paying the reveal cost of 5. The Wizard can then reselect one of the Warlock's equipment to destroy. For example, suppose the only equipment the Warlock has is a Lash of Hellfire (cost 8 ). In that case, the Wizard could reselect that, paying 2 additional mana, and destroying the Lash of Hellfire, or he could just cancel the spell instead. (If he did not have the 2 additional mana available, he would have to cancel the spell.) If the Warlock had an equipment with cost less than 6, and the Wizard chose that piece of equipment instead, the Wizard would not get mana refunded.
Example: A Warlock casts Force Push on a Wizard without paying the additional 3 mana to push through a wall, and the Wizard reveals Reverse Magic, paying the reveal cost of 5. The Wizard could pay the additional 3 mana to push the Warlock through a wall if he wanted to. (Effectively you recalculate the cost, and with the additional cost the new cost is 6 while the original cost was 3, so the difference is 3 and that's what you have to pay.) If the Warlock had cast the spell and had paid the additional 3 mana, then the reversed spell could push the Warlock though a wall without the Wizard having to pay any extra.
Only one of the targets of the reversed spell needs to be the original spell’s caster. The caster of the reversed spell is free to select any other targets, as well as any other choices made “when you cast this.”
If a spell has multiple targets, a Reverse Magic on any of the targets will cancel (and reverse) the whole spell.