I have never heard those rumours and I doubt they are true. I think the X-Men cast all got along well with each other or at the least the original ones did (Halle, Hugh, James, Famke, Anna, Patrick, Ian, Rebecca) Also regarding your comment about storm's inconsequential role. I would be inclined to agree with you but we must keep in mind that Matthew Vaughn had a hand in the script and we all know from his X3 days that he liked the character storm so he might have written a good role for her. t wouldn't have been hard to come up with inspiration as Storm was in the original dofp comic. If what i'm speculating is true than I doubt Singer would immediately write her out. It would be a disrespect to Vaughn who is still producer of the film.