I'm guessing some sort of standard British, but I do think it's important they all have the same accent. There's usually some racial diversity in a region, but the Two Rivers would definitely have a consistent accent.
Ok? There's this thing called working out before a movie or TV show? Chris Pratt looked completely different before Guardians of the Galaxy. Charlize Theron looked completely different in Monster. Christian Bateman has gone from one extreme to another in movies (not that I condone that). But...
Omg I love the Perrin casting so much in particular, he looks so much like I pictured him. Egwene is my other favorite, although I really like them all! Rand I'm slightly more meh on, but I'm definitely not opposed!