Val needs a direction to really land with readers because right now, everything he has is essentially tied to another character people like more and he has nothing that sets him apart aside from a pretty good costume. More than anything else, I think he'd benefit from an Elseworlds story focusing on what makes him different from Clark and Calvin. Strip away E2 and everything involved and build him from the ground up.
She is a character of 50 years with many stories and publications and you relegated her to a prop in Val's story. That's why a lot of PG fans don't like Val and how DC threw PG at him to give him a story. There was no buildup, she just appeared in his orbit and now she was his girlfriend. It was offensive to people who liked PG beforehand. She is not his love interest much like Black Canary is not Oliver Queen's love interest. They share a relationship, but each are their own IP. When Dinah (or PG) are treated as just someone's girlfriend is when those characters are their least interesting, and frankly it's reductive of them as characters in their own right.
That run did a major disservice to Power Girl (the entire New 52 did) to try and prop up Val. Throughout her tenure in the New 52, Power Girl was either used as arm candy for a male hero or just spinning plates because they didn't really know what to do with her. From being an accessory to male heroes to turning her into Supergirl proper, that era was destructive to Karen in ways her fans understand but perhaps people who don't much know about her don't care.
I'm sorry, but I can't respect anyone who tries to hold up any New 52 developments for Power Girl as a fan of her character given who she had been prior and how they had to mangle her personality and character in order to be the character we got. Gone was the outspoken, sassy woman who refused to be seen as "Superwoman, Supergirl or woman Superman or Superman's cousin." Gone was the woman who refused to be someone's plus one. Gone was the woman who didn't just go weak in the knees and get turned into arm candy as a status symbol. Gone was the self-actualized woman we came to love. I don't think anyone minded her getting into a relationship, but both she entered during New 52 seemed to be more about "look, he's with Power Girl" than anything because Karen got nothing out of the deal. Both times, it was to benefit the male hero. Were the character real, she'd be writhing under her own skin at being turned into an accessory.
Could the relationship have worked? Maybe, had they actually shown us why those two had chemistry instead of a flashback that they totes knew each other and wham, they love each other. That relationship was stillborn and trying to prop up Val by shitting on Karen's identity isn't going to endear anyone to him that respects women. Val needs his own story, not to crib off of other more popular characters.
Calvin's got a lot more going for him than being based on Obama. That's akin to saying "Moses-- er, Clark Kent, right?" Come on, man.