Sounds like we have the Same Springfield. A fellow shooter puts about 20,000 rounds a year through his and various parts break each year. I agree with you that steel is the deal. All I would ever do this Springfield is add steel parts where necessary. Other than that, I won't change a thing.
Customizing 1911s is fine and I have a Caspian frame custom built that is having some issues. But it's an IDPA, practice, and fun gun. My Springfield is near stock and it's the one I stake my life on if needed. KISS is the best recipe for a self defense handgun, IMO. I shoot my Springfield in IDPA tyepe events occasionally as well. The 1911 is an excellent design and as long as you have quality, steel parts where needed, they really don't require much more to go bang when necessary.