I think Bella casting makes sense. She is like 17 in real life, she will probably be around 18 when shooting. but even at 18 she has one of them young looking faces that can easily pull off playing an 14yo. If Last of Us does well, and they do a part 2 she will have had an extra year or 2 to get more inshape and mature a little to play a 19yo Ellie even known she will probably be the same age as Ellie in part 2 or just a little older is part 2 happens. Also I think the role may of went in her favour, because she can play the guitar just like Ellie. As for looks she don't really look like Ellie because of her dark features like her hair and eyes. Were Ellie is a redhead with greeny blue eyes ect, but that can be sorted with hair dye and contacts or even CGI ect. But to tell you the truth i don't really care if the make her look like Ellie from the games or not. She just has to capture Ellie's spirit and emotions which is going to be one of the biggest challenges for Bella. I liked her in GOT but ain't seen her in anything else.
As for Pedro same as Bella both never came on my radar to play Joel and Ellie but I'm happy the cast him cos he was great in Narcos and GOT and as the mandalorian. So not worried about him playing Joel I'm sure he will do Joel justice.
Now the rest of the cast will be interesting to see who gets cast to play the others characters in the first game and maybe 2nd if the follow part 2 which I'm also a fan of. So be interesting to see if the ever cast Abby.