Do this location has option to return car after business hours ? If Yes then where would be the key drop box ?

Yes it does have a drop box. I dropped my car off after hour

Yes they have a drop box you can leave the key in it just make sure you have all your belongings if not you would need to come back for them. The drop box is by the front door they usually have a sign that say so

Yes

I believe so not a hundred percent though