I think Storm cleared that up pretty well.
As for the other points:
Cloud forgetting, I'm sick of explaining this, please explain why every single time I've went through this I've been wrong before asking yet again.
The damage around Jenova's container, I doubt she'd be gentle in opening the door, Cloud would only need to break the lock or use a terminal or etc.
Cloud getting out, this needs to be explained nomatter what theory you go with, there's no reason the Cloud theory should be the corner defending it.
Jenova getting herself out requires many assumptions, and explains very little.
Jenova has to be able to get out, unlikely given Shinra wouldn't put her in a container that was THAT easy to escape. If that's true or not, why did she do it at that EXACT time. I don't know how many years Jenova's been stuck in various places, she chooses the ONLY time she has access to a puppet with the ability to free her. By only, I mean ONLY. Cloud's cell was opened at random. Jenova got lost on her way to Shinra and headed for the cells first.
