Couple quick points:
1) You mention Rico's career was killed due to the gimmicks - Rico was probably as over as he ever was prior to being fired. At his age, he was never going to be given a big push, but he was able to make the gimmicks work, and get over in spite of them.
2) You mention HWA a couple times - IIRC, the only guys to make it out of HWA and onto the WWE roster are Charlie Haas and the WCW buy-outs, so I wouldn't exactly call HWA a breeding ground for WWE talent. They probably refined some of the guys, but they really didn't take anyone from scratch -> WWE ready.