Time Lord/Headscratchers

I know TARDISes are bigger on the inside, but...

How would Tohno Shiki be able to enter his TARDIS (i.e. a knife) when the entrance is several times smaller then he is?

• The entrance is full-human-sized, its just as small as a knife-blade. I assure you, it makes perfect sense in twelve dimensions.
• The Doctor Who Expanded Universe has a Spaceship Girl TARDIS. Somehow she kind of opens up to form a decent-sized entrance, so people her size or bigger can walk right into her. It's in-universe High Octane Nightmare Fuel. So, the upshot of this is that probably the knife would not, when opened up, look like a knife.
• The same way you can step through a hole in a postcard. (If you don't know how to do this, look it up).
  • More Nightmare Fuel when you realize it involves cutting it up.
• If you were to open a hole into the tardis from the outside, what would happen?
  • You would have a hole in the tardis.
• What happens if you put a Portable Hole / Bag of Holding inside a Tardis?
  • You would have a Portable Hole / Bag of Holding in the tardis.

Why is the Warden's TARDIS Superjail?

Superjail is a series of buildings and made into a volcano. Shouldn't Jailbot be his TARDIS?

• • Because even if then the jail is still bigger on the inside.