I think they need a villian that isn't just flash's evil twin for a change.
Agreed. I assume the thinking has been that only another speedster represents any real challenge for the Flash, but if that's true the show needs more creative writers.
Speedsters have always been problematic in comics because if used to full capacity, pretty much no one should be able to beat them. Granted, depending on the villain's defenses, they might have a problem taking the bad guy down, but evading an opponent's attacks should be effortless even if "surprised."
I remember a comic story not long after Wally West became the Flash. He was sitting in a movie theatre minding his own business when suddenly everyone and everything in the theatre froze. He quickly realized that his hyperfast reflexes had reacted to something and kicked him into speed mode automatically. Looking around, he saw a gunman at the back of the theatre, who's already fired several rounds from a high-speed automatic rifle or machine gun. His reflexes had kicked in the instant a bullet touched the back of his head, before it began to penetrate. He'd had no chance to hear the shots before that because the bullets were traveling faster than sound. He had time to disarm the gunman and move around the darkened room, collecting bullets from midair.
With reflexes like that, dodging Captain Cold's gun or moving behind Black Siren as soon as she leans forward to scream shouldn't be a problem. TV-Barry is unlikely to ever develop those reflexes -- he's only fast once he gets going -- so he can be challenged by almost anyone.