I think there are 4 total active, but only 3 are able to be completed. There are the first two you completed already (watch and pills), and then one related a lab, that is indoors. You get it in front of the hospital. The bomb mission is probably not actually a thing, so I'm not sure why they keep giving it to us.
To your other questions, yes, there is just one instance of the city. Yes, there are only a few mobs that cap at 9. As far as what is needed to be tested, probably combat mechanics and character creator mostly. Report any bugs you find in either, as well as any features you'd like to see improved in general.