There is no key included. If I remember correctly, you can change the code as follows: Set the current code, open the case, press the button in the case. Then set the new code and confirm with the unlock button. Test again with the case open :-) The instructions for this (multilingual) were in my case.

+- 48cm.

A 16" laptop does not fit in the laptop compartment of the Wenger Syntry Business case. The compartment is designed for laptops up to 14 inches (35.5 cm).

Yes, it fits easily, even with a Sleve cover.

It can be locked, but you will need a small padlock. This is not included in the scope of delivery.