This is something I can get behind. Imagine a sandbox like that! If only you were working there.I still think the most elegant solution is to reveal that Nuperman and his Lois are the real Superman and Lois....of a parallel universe. When the universe got rejiggered with during the finale of FLASHPOINT,Superman and Lois were missing on Tellos. So,someone...the Time Trapper,Dominus,Mr Oz...dr. Manhattan.... whomever... plucked Nuperman and Nu Lois from their native timeline (a rebooted pre 1986 Earth 2)and plugged him them into place,altering the New 52 verse around them to mirror their memories in the other timeline. Bring Nuperman and Nu Lois back,have them help Superman and the other heroes save the universe at the end of this whole Rebirth mega story,they discover the truth about themselves and after some goodbyes and farewells to the heroes of Earth 0,they return to their native timeline...which is essentially the New 52 universe...the REAL Earth 2.
Bam. Done. Superdad and family stay on the main earth,Nuperman returns to his real timeline where he can continue his life where he left off. I'd pretty much keep everything up to Truth canon for him and pretend everything after that didn't happen. Go and beg Greg Pak and Kuder to come back and write his new monthly book... SUPERMAN: MAN OF TOMORROW and turn them the f--k loose and let them do what they want with him. Go nuts. have him date Wonder Woman or Batman I don't care.Perhaps have an annual Crossover special for the two Supermen to cross earths and team up.
There. Fixed it DC. Nuperman fans get their Supes back, we all get another kick ass Superman title to read with room to explore a separate universe to experiment. You can cut me a check anytime now.