Re: Superman's power level
Very interesting quotes. And bang on the money too.
A storyline involving Brainiac would certainly be suitable if they're trying to find a villain who is more interesting than just a physical threat.
Brainiac is complex, hugely intelligent and has various means (only some of which are physical) of attacking Superman. He's a manipulator also. Tie in some kind of background where Brainiac is involved with the destruction of Krypton and you also have some kind of emotional resonance for Superman.