Level 1-8 I was the ultimate good guy and I have to admit the game was getting boring then I just decided to turn total killer. I even went back to Goodsprings and wiped everybody in the town out. Have I ruined the game by doing this? What problems might I possibly encounter by doing this? 3 NCR soldiers just told me I have 3 days to clean up my act or they will be coming back for me. Lol then the game froze for the 3rd time tonight. Thanks to the reponses in advance.
It really depends on who you killed, like did you get a quest failed pop-up?
If the only people you killed were in Goodsprings you should be fine.
About the NCR,
Spoiler your rep does get reset at some point.