Your Plan seems sound. However, the Industry isn't, and thats the problem. I worked for Comair for 18 months between Active duty and my current Job, and some of the jr Capts I flew with upgraded in like 18-24 months. That stopped the month I got there, with the Guy I went thru Sims with being one of the last Capt Upgrades while I was there. I think over the whole time I was there, (May 03-Nov04) I saw maybe 1 or 2 up grade classes.
My point is the situation at each Regional is extremely fluid, mainly because they are dependant on a mainline partner(s). If you can time it right with the right regional, your plan might work. But your plan also happens to be everybody's plan, and as history as recently shown us, it isn't as easy as it sounds.
Also, Don't forget to network. Much more important than TT and almost as important as Turbine PIC.
Have you considered the Military? Better networking, Better Pay, You'd probably do well with your previous time. Plus, What better way to spend your 20's?