True, but there's also CG to help that problem. Assuming Nona Gaye got the part, and was signed on for 3 film, even if she noticably did age, they can totally do what they did with Patrick Stewart and Ian McKellen in X3 with making them look younger. Personally, I think Nona looks rather youthful, and it's not like Storm is that young either. She should be in her 30s, which Nona is. Same with most of the other X-Men. They shouldn't be in their late teens or early 20's.
You're right about Pine working more as Iceman than Cyclops. I still don't think Duhamel is good enough for the part. Yes, there isn't a need for an award winning actor, but there is a need for a good actor. I just don't think Duhamel has the chops. All the X-Men have to be good actors. Otherwise, what's the point?