Halo: Combat Evolved
No it does not, it comes in a disc sleeve.
Yes it does. Microsoft made a few original games compatible on 360 and the Halo series is one of them.
They’ll do their best to keep it in good condition but since it isn’t produced anymore it can be hit or miss.
No, you can only order them online. If you can get them shipped to your store, it will have a "Pick up at store" button under the "Add to cart" button.