Unfortunately, I really think that the X-men universe needs of a better film series without a lot of mistakes like the recent trilogy has. For example: Charles Xavier appeared bald and walking in X-men Origins: Wolverine, however, he became paraplegic during the events of X-men: First Class that is before X-men Origins: Wolverine.
All my cast was chosen because of I think that they are good actors with features that resemble of their respective characters as for example: Mark Wahlberg often plays angry and moody characters like Wolverine is; Emily Browning has the same body type of Shadowcat at the comic books; Deborah Ann Woll and Jessica Chanstain are redheads like their characters; Lyndsy Fonseca has a sexy body like Rogue.
Fancast
X-men Team
The Brotherhood of Mutants