I personally prefer the prominence of Flash as one of the first two major heroes in his universe.
I also can't imagine the show being half as good without Tom Cavanaugh, so if you told me before the series began that Reverse Flash wouldn't be in the show until season 2-4 I'd be cool with it, but in hindsight his arc in the first season was great and he is consistently the best actor week in and week out.
I also don't like the length you suggest. While it could lose 5-6 episodes I think 6-13 would lead to a lot of lost character development. I also enjoy well done villain of the week episodes, as it makes it feel like a real comic world. Not every week is a huge crisis. Especially considering the Flash has a massive rogues gallery to play with.
I don't really want all my tv to feel like 1 long movie. Also season 2 of Daredevil (which I love) failed to wrap up a single plotline because 13 episodes didn't give it enough time. Daredevil also struggles to balance giving time to Matt's personal life and relationships. They never showed him, foggy and Karen becoming this super tight unit, they just asserted it happened and you had to buy it. I also have no clue how they survived in season 1 since they clearly never did real work. The best example is early in the show when Matt went like 3 episodes after the premier almost never interacting with Karen and Foggy, his main supporting cast, because they needed to pound out the Russian story by the end of episode 5. In a longer season you could've had a couple less important episodes to build relationships and character development early in the year before having Matt break off from the others for 3 episodes. Similarly after that arc Night Nurse is just written out cause they no longer have time for her, which would be fine if they hadn't spent so much time building that up over other relationships.
Things I like from your pitch:
1) A smarter Barry. Yes please!
2) Show lasts 4 or 6 seasons. I've never seen a show go longer than 6 without a serious decline in quality.