Eh, I'm not a huge fan of the "reinvent classic Rogues as superhumans." I actually like the idea of Keystone City being a "City of Mad Science", with the Rogues being scientist-criminals out not for money so much as prestige.
I just don't think you can use most of them as the main villain for the Flash, and expect the GA to take it seriously.
As for why I say the Trickster is valid, its because cleverness and intelligence can be a credible way to challenge the Flash. All the speed in the world doesn't matter if you don't know what to look for, for instance.
My own hypothetical first movie plot goes something like this:
-Keystone City is overrun by science criminals, the police are helpless
-Forensic investigator Barry Allen has a science accident that gives him superhuman speed
-With some bumpiness, the Flash thwarts various Rogues in their crimes, albeit isn't quite able to keep them from escaping
-Bitter, the Rogues are gathered by a mysterious criminal calling himself the Trickster, who offers them a plan to work together and take down the Flash
-Said plan almost works, but through cleverness as well as speed, the Scarlet Speedster manages to defeat them all, and this time, they are captured, their hideouts found, their equipment confiscated
-. . .which was the Trickster's plan all along, as he had infiltrated the police department. All the confiscated tech and schematics? Stolen. And now the Flash has to defeat the Trickster, who could never have invented half these devices, but is deviously clever in how to apply them to take down the Flash. . .