With a given ammo, recoil spring rate will vary according to mainspring rate, MSH construction and FPS geometry. You can't necessarily expect a Colt spec recoil spring to improve a SAM unless you also change out everything else to Colt spec.
This is why people end up with screwed up 1911s...an infinite number of companies building an infinite number of renditions of a pistol in which several factors need to be balanced to make each step work.
If that were my gun I'd try a different extractor, and I don't like ejectors extended to that length so I'd probably end up taking it down some.
If the brass is hitting you, the problem is not just that the brass is coming out too fast, it's coming out the wrong direction. I'd put a Wilson extractor in it and see if that corrects the ejection angle. You could address the geometry of the existing extractor but unless you know what you're doing, you may not improve things because you won't recognize the problems.