Well that may be one of your problems. You are going by pictures. I have yet to see a performance from Ryan Gosling that convinces me he could pull off Batman. Even when he is playing a badass in a film. Like I said I like Gosling and he is a talented actor...but just because an actor is talented doesn't mean they are the right fit for every character. Not saying I would roll my eyes and throw my hands in the air if he was in fact the next Batman. I would hope I was wrong and he surprises me with an excellent portrayal of the character.
And what I'm looking for in an actor? Well I personally think Michael Fassbender would be amazing as Batman but that's just me. He's a little too old though at this point sadly. They are probably going to be looking for someone around Cavill's age.
No im not just looking at pictures. I think his performance in Drive and from what ive seen of him in Only God Forgives footage, he would play it well. But yes the voice is the only thing holding him back in my opinion, that part could turn out great..a good transformation, or horrible because he simply can't pull it off.
Fassbender was always my number 1 choice but I gave up because of the Magneto thing. I also don't remember him pulling off a perfect American accent, maybe im right or my mind is blank at the moment.
Fass just turned 36, that wouldn't be a problem because Cavill is portraying a 33 year old Clark in Man Of Steel. They could always act as if Fass is a couple years younger than his actual age.