can thin strips of wooden dowel be used as carbon fiber replacements?

Absolutely! the best substitute is barbeque skewers. Bamboo (what they are made from) is amazingly strong for it's weight. Look for the 12 inch ones available at grocery, dollar stores and Walmart/Kmart, etc. I once found 14" skewers at Target. You can get a bundle of a hundred for 1 to a couple of bucks. There seems to be two diameters about 1/8 and 3/16 inches. Good to have some of both if you can find them. I've done over 30 planes and haven't had to resort to CF yet! funperbuck!

On the other hand, if you're gonna do a leading edge reinforcement, a 1/8 to 1/4" hardwood dowel available at Ace hardware, Home Depot, etc will be better as it will give a perfectly straight LE with about the same amount of reinforcement.