A:AnswerI would caution you using it within the case. The little straps at the bottom of the case (to keep it open) now enter into play and if you close your laptop and those straps are stuck in between the laptop, it has been reported to crack your screen! Take it out of case…safe, sound, venting properly. I think of my case as a safe transit option only and remove my laptop when using. IMO
A:AnswerThe case could be locked with the zipper handles - they finger holds are big enough for a small lock, as might be used for luggage on any suitcase. However, if somebody is intent on getting into the case, a knife could easily circumvent that precaution.
A:AnswerI would not recommend this for the MacBook Air. It would be to tight of a fit and you would probably be frustrated over time and then consider this to be a bad purchase or a bad product. The MacBook Air has a larger chassis then the MacBook Pro 13". Remember this was made for the MacBook or MacBook Pro 13.