Have to agree with the above statement, you draft BPA and play to win now. Having a youthful team filled with prospects looks great on paper, but usually those players go out and struggle for a few years before they come the true studs that they are. There still are exceptions, braun/longoria, but they are just that, exceptions, not the norm. So while you may think your team looks sexy with all those harper, tallion, trout type players, guys that draft jeter, aram, ibanez when he first came to the phils will be winning. Sure patience will pay off with some of those guys, but the reality is, all top prospects don't work out. So you could have the top 5 prospects, and odds are that only 1 or 2 will become true studs.
In summary, draft BPA, if there is a tie between who you like more, go with the younger guy. But as you said, taking castro over jeter was simply a mistake IMO. Same with the hellickson pick depending on who else you passed up. I do like your top 3 picks, although taking a SP in the 2nd in a dynasty is risky, but its the past so no point on focusing on that.