2. shutter speed
4. electronics eg the modes should work as they are supposed to
7.mount a lens and a flash and see if all 3 can communicate
9..ie a lot to check
It depends on what type of camera u are planning to buy.
For SLR, there're more to check.
Maybe u can state the type of camera u are looking for. Then we can start from there.
To note; U can't probably can't check 100% & discover any faults in an hour or so of testing. Some intermittent problems surfaces after a days or even months. That's the risk u have to bear for buying a 2nd hand items.