Hmmm.....not sure why you'd want to change out the hammer, but I'm sure that would be no problem....I've read of issues with the regular PT1911 ambi safety, but not everybody has that problem. Apparently some people have experienced the safety on the right side of the gun falling out. I have the PT1911ALR and I haven't had this issue - I've just read about it in posts. I've not heard of anything else having any problems on the 1911 series.
Welcome to the forum, by the way.