Stick with me....

At the end of VOV the camera focus's onto the TARDIS yale lock. Was this for arty reasons or was this to suggest that the cracks are a key hole?

And yes I know the keyhole isn't identical to the cracks - but are all the cracks identical?

Could be, although I don't know if it's just allegorical. there's def been a lot about keys and locks and things being let in or out this series

On the other side of the cracks are

That would be awesome, CoalHillJanitor!

Also ties in with my theory that

Yep. Boxes and prisons and opening and snapping shut.