Can somebody please tell me which component is "the one that is failing but not completly failed yet"?

Which component will allow power to be sent to the gas valve to soon?
It seems simple, control board, but I would hate to spend $250 for the component only to find out another component was causing the problem. Yes Bubba, I know, that's what techinicians are for.

Since it's working at the moment, I can't troubleshoot with a multimeter. So which is the most likely culprit?

BTW, what is wrong with keeping inexpensive parts, such relays and capacitors around? System stops working, install the most likely component, and then call for service if it is still messed up. Compressor fan slows, change the capacitor, blower fan quites, change the capacitor, it's just too easy and cheap not to do so.

Bubba, If a light bulb goes out, do you change it first or call an electrician? If your faucet starts leaking, do replace cartridge and orings or do call a plumber? If you want a new plant in your yard, do you call a landscape company or do you plant it yourself? If your computer locks up, do you call Microsoft to come fix it, or do you press control alt delete? If your DVD drive quits after warranty, do you send your computer back to have it replaced by manufacture, or do you order a new drive on the net and install it yourself? If your check engine light turns on, do take your vehicle to the dealer or do you drive to the nearest autoparts store where they will connect a scanner which tells you the fault? If a squealing sound starts radiating from under your hood, do you replace the belt and check pulleys/bearings, or have a tow truck delivery your vehicle to the dealer?