I sent following questions to FFG and received answer from Damon Stone.
I hope this answer won't be overrulled)
> I have several questions about control of unique card, related to each other.
> 1.Player A has in play Balon Greyjoy(King's Landing 30), Player B has in play Ser Preston Greenfield(King's Road 57). After copy of Ser Preston discarded from Player B deck, Player A triggers Response on Balon Greyjoy and puts that copy in the Shadow under his contol.
> The Question -- may Player A bring stolen copy of Ser Preston from Shadow, given that Player B still has in play his own Ser Preston?
> 2. The plot 'Breaking and Entering'(Lions of the Rock 51) are revealed. Player A has in play Myr (Beyond the Narrow Sea 76). Player B wins the intrigue challenge against player A, and player A discards copy of Myr as part of the claim.
> May Player B put this copy in play under his control for the effect of 'Breaking and Entering'?
> 3. Player A has in play Hugor Hill(Beyond the Narrow Sea 4) and player B has in play Willas Tyrell(Beyond the Narrow Sea 9), and also copy of Willas Tyreel in his discard pile.Player A won unopposed challenge with Hugor Hill against Player B.
> May Player A put in the play under his contol copy of Willas Tyrell?
And the answer is no to all of those.