Regarding the oak, you need to put an eyeball on the stock....or get a trusted opinion. First of all, verify the dimensions...particularly the thickness. If it is exactly 1" thick and rough sawn, you will be OK for deck boards that are supported by 16" O.C. Next test: if it is not split and cracked, knots are tight, and the boards are flat and straight, take it. (At this point, I must remind you that I have no experience with the weatherability of of oak in exterior applications. Based on the approval and input from others that have, I assume this part to be a given)
Do you have power surface planer (or a pal with one?) One very lite pass on each surface will knock down the rough texture and not remove too much stock. You will not remove all the saw blade marks, but who cares?
