How do I make a block that keeps it's inventory when pushed by a piston? And other problems.

I'm trying to make a mod that makes it so that you can create the Command Block in survival mode, and I'm trying to make it so that my custom Crafting Table will keep it's inventory when it gets pushed by a piston. I'm trying to make it so that you can mimic what happens in Minecraft: Story Mode in Redstonia when Elleguard tries to create the Command Block with 4 crafting tables in a '+' formation. Could someone help me figure out how i could replicate how this happens?

What I nee help with:
- custom crafting table keeping it's inventory when pushed
- custom crafting table sensing when it is facing the same air block as 3 other custom crafting tables(oriented at the same block)

-sensing when each crafting table has specific items inside of it (one holding a specific set of 9 items, another holding a DIFFERENT set of 9 items, etc.)

If anyone would like to help me develop this mod, let me know!