From the looks of it, the previous owner did the following:
- removed the stock air box and put in aftermarket intake - then took it off and left your intake open
- took out the passenger seat to do some drag racing / weight reduction - it will give you an airbag and seatbelt code
- get an aftermarket tune (not going to suggest anything - get what you like)
- remove the airbag/seat belt code via Tune or ODB2 tool
I've driven my car without intakes before, its not bad until you get something sucked into it.