Green Latern doesn't need to all that young. The ring does all the heavy lifting, after all. John Stewart had a military career before becoming an architect, nothing wrong with the character being in his 40s.
Downy and Samuel L. Jackson are older than everybody else in Avengers, but it fits the background of their characters.
I agree totally. And even though it's not like Barry's hair color matters much, Ezra is just way too quirky/gothy in everything I've seen of him. Barry Allen isn't quirky or gothy.
This is nothing like how some people doubted Ledger as the Joker when he was announced; most of those people only knew him as "guy in that gay cowboy movie I didn't see", and assumed the worst.
I reminded of when Adam Driver was rumored to be playing Dick Grayson. It's not that he's a bad actor, but he'd be *completely, utterly* wrong as Dick Grayson. For that matter, he wouldn't be a natural fit for Flash, either, but at least he'd be better than Ezra.