where do you people get your imagination from?
Try engaging an autopilot with those fault messages. Oh ye. it won't.
And speed and altitude functions are not unique at all. Yes if the pitot probes only are affected then you will only suffer speed problems however if your static ports have a problem you will witness both altitude and speed issues.
All BEA are trying to do now is ensure a professional release of the information because it has been established that the a/c was technically fine. Now that doesn't leave many options.
Until we know why the crew didn't avoid that weather front we won't know why this happened. We already know what happened.