If you're asking for my long-form fanfic, one day when I finish it then perhaps I'll share it for everyone to eviscerate, but if you want a more broad summation of what I think would be a good direction for the main line of books?
I would scorch Earth and rebuild the line from the ground up. Start with three books: Superman, Action Comics, Supergirl. The intent would be to double the books in three years with more of the Super family, among them Steel series and a Lois Lane book (which would be more of a detective/crime book and focusing on building up Metropolis). The last one would be a wild card based on what we're seeing across media, sales information and so forth as the emergent darkhorse-- so Superboy, Krypto, whatever.
The primary focus would be a back-to-basics method of telling stories in DC with a renewed focus on Metropolis, the Superman-centric corners of DC and generally really showcasing the coolest parts of the IP. I'd push for each book to have some degree of civilian/ancillary characters that support our hero instead of just borrowing a lot from other IP (Batman, Flash, etc). There could still be crossovers, but we have a Batman/Superman book so is there something we can do with Jimmy? What about Steel? Mon-El?
Each book would be telling its own story but we'd get together after a year and do a Super crossover that doesn't spill into the mainline stuff and then break out from there and keep rolling.
With Superman specifically, I'd like if one book went full cosmic and one stayed Earthbound to provide both flavors the character's capable of and would seek talent interested in that.
Supergirl's mission would be "find a niche that isn't just Clark-lite." Lose the reporter aspect, she'll never truly shine if she can't be allowed to find her own way.
Lois, as stated, would get the Metropolis book and would focus on what's happening in that city as well as some crime stories.
Steel would be my socially conscious Superman. I fully believe Clark is left-leaning, but even in this hypothetical situation I don't think I'd ever let him do what I think he would because AT&T is probably too cautious with him. Steel? I think they'd let him knock some heads around. Closer to a Siegel/Shuster/New 52 Clark but with the perspective of someone older. Unlike GA Supes, he'd continue pressing his advantage after the usual strongman bit and try to instill more permanent change. I don't mean that in a lethal way so much as he'd use his intellect and resources to solve the problem at the source
after he did the superhero smash and save. :P
Last book, probably Superboy, Power Girl or Legion of Super-Heroes (possibly with Superboy). Depends what I'm allowed to get away with. Hell, if I had my druthers it'd be Power Girl or a Maxima pitch I've been cooking for a while.
Now scroll back up to "if you're asking" and that's when DC fired me so don't expect to see anything from me.