What does the bike weigh now? How did you pick your five pound target? Have you considered selling the 'Dale and replacing it with a bike that has a lighter frame (C'Dale frames aren't reputed to be especially light, and moving to caliper brakes would be an easy way to shed grams)? Your contemplated upgrades (wheel$, crank$, fork$) could set you back as far as the cost delta for an entirely new bike... and in the end you'd still have the original sturdy-but-flabby frame.

... just a thought!