So just so I understand it, your theory is that mystique recruited Beast, then when the sentinel attacked the capital mystique replaced Beast to make it look like he had died. When she was buried she transformed into a gopher or something and dug her way out. If this were true it would mean that this mystique and transform into inanimate objects, which is the 616 mystique couldn't do. I could see a teleporter who is wearing a psychic dampener making the switch, making it appear that Beast had died because his psychic signal disappeared.
with Mystique sneaking around and beening in some many diffirent books doesn't make you think that xavier has something going on that for some reason he is watching all that other big players in the world. who would some how be able to stop him iin his grand plan to overthow the ?