One of the great things DC did after Crisis was Vertigo. Basically, an indie line made by a big player, featuring property interpretations that didn't really belong in the DCU.
If you were going to launch a new imprint, what would it be? Equally important, if you remove characters from the DCU, how would you compensate for the hole you create?
For me, I'd say cancel Detective Comics as a title, relaunch it as an imprint, and migrate the entire Bat-Family out of the DCU (minus anybody overtly superpowered, like Clayface or Poison Ivy [unless you dial them way back], plus some non-bat characters that might make a good fit, like Nemesis, and Dr.13). Lots of plausible horror in addition to hard-boiled mystery, but take O'Neal and Adams as the entire imprint's guiding star.
In the main DCU, either kill the Batfam, or Crisis them out of existence, and fill the niche with a combination of Mr. Terrific, Green Arrow, Manhunter (Kate Spencer), and Hawkman. If The Powers won't abide that, let Batgod remain in the DCU, but treat Detective as a a separate reality.