I do not know what to tell you about the firing issue, if you could post pictures of the parts it may help. Does the firing pin dent the case?

The safety/trigger spring changed over the years of production, some had the ears and some did not. Without checking I do not know which type would have been standard for a gun in the serial number range of yours - when I get some time I will pull a stock or two to see. The safety arm is what pushes on the trigger and the spring you are referring is what makes it do that. If the trigger is working that spring is at least doing part of it's function correctly - again pictures might help.

I sold one of these springs a couple years ago and sent two springs, one with ears and one without, the buyer said only one seemed to work correctly. I have not tried this myself to see if they are interchangeable but from his feedback it seems there maybe enough difference that they are not, this would also suggest some difference in the safety arms (other than the ears both springs look the same to me).