The trigger group symptoms don't make sense to me as well, answer of course you'll know once you take it apart and see. Best I can figure is there was a shift in the stock that has influenced the trigger/safety. If it were mine the very first thing I'd be wondering about would be checking the headspace just to see if it has indeed changed. If it hasn't then you may well have dodged the bullet. Varget does funny things like lower in pressure on some compressed loads. 8 grs over max though is a "pretty gross" over load though. If the headspace checks out I'd probably disassemble it and check it out the rest of the way. If the headspace has increased over what it was then the concern level increases exponentially. If you can't do the work the gunsmith check is a good idea.

Ron