The Starkiller hub is the last hub. Unlock all parts of the hub by completing the 9 Starkiller levels.
Collectibles
The Starkiller hub has 5 Minikits and 10 characters in carbonite. There are also 6 side missions associated with collecting some of those Minikits and characters in carbonite.
Minikits
Minikit 1
The first Minikit is located aboard the Millennium Falcon. Break open a container with a large crack on it to get the goods.
Minikit 2
This Minikit is on top of the wall on the left as you exit the First Order base. Use a grapple gun to pull it down.
Minikit 3
This Minikit is partially buried in the snow. Use the Force to lift it out.
Minikit 4
A minikit is the reward for completing the Ace TIE Pilot side mission. This requires you to repair a TIE fighter and involves strength handles and an astromech terminal. Once the TIE is repaired, you need to take it out for a test flight and fly through all the race gates within 44 seconds.
Minikit 5
Complete the Stormtrooper School side mission to collect this Minikit. You must find three data cards and bring them back to the instructor. You will need to use the Force, activate a First Order terminal, and defeat some stormtroopers to get the cards.