Faith is good - if you believe that the guy is good enough, you ideally need to give him 5-10 tests to prove you right or wrong; although I don't always agree with their selections, I don't agree with the likes of Taylor and Khan being given only one or at best two tests to prove themselves.
Hick and Ramprakash are interesting cases. For what its worth, I don't think Ramprakash would have "made" it - for all Bell has occasional mental frailties, he doesn't quite match Ramps' ability to mentally self destruct, and I doubt that any amount of faith being shown in him would ever be enough to relax him. Hick is a tricky one - I don't think that the change of regimes would necessarily have made that much of a difference; however, the lack of genuinely world class fast bowling in most opposition sides would.
A couple of other names spring to mind as being ones who were cast aside by previous England regimes; Matthew Maynard and John Morris. Both were talented batsmen, but never really got the run of games in the side that was needed to see whether they had what it took.