Justin
There are a great deal of variables involved in your questions to get good helpful answers. I am not an expert in this process.
But, my father owned and operated a saw mill for years. I accumulated personal observations but very little learning in the whole process. He always stacked drying lumber just like your picture. Some of the thicker pieces sat for years. Some thinner stuff, not so much. Different wood took different drying times. I still have a great deal of his walnut, oak, cottonwood, cedar, etc. It is stacked in my shed, just like your picture. Some of it is decades old.
1) You indicated "green" rough cut lumber. I do not see that indicated in the FB post. It says rough cut. I do not see "green" rough cut. The reason I say this is that from looking at the stacking method (spacers) it looks like it is already in the drying process or dry stage. If you could get a moisture content it would help a great deal to get a good answer. It may be fairly close as it sits. The spacers are the most used method for naturally drying wood. Kiln dried speeds up the process. But it leads to problems also.
Dad always just cut it, spaced it, ventilated it, kept it dry, and let it sit. You may get some twisting, cracking and warping depending on your climate, temp. changes, and humidity. Some folks seal the ends with wax. It may help to reduce the twisting and warpage. It may not. From personal observation, I am not convinced it helps all that much. But, we lived in Nebraska with bigger temp. changes, humidity changes, and other climate issues.
2) I have seen some wood take years to dry. Like 2-3 years. Usually thicker pieces like fireplace mantels, and gun stocks. It really depends on the climate and the humidity. Arizona is a great place to have wood air-dried. Very low moisture, low temp. swings, and very low humidity for the most part. Way better than here in the Midwest.
I'm sorry I cannot give you any better answers. I will caution you to make sure the rough sawn lumber is thick enough to be planed and still have enough width for a knife handle. Planing will take some off each side. Usually more than you anticipate. If you start at 1.5 inches and only remove .25 inches you should be good to go fro scales and blocks. For me, it is hard to get a decent set of scales from anything less than 1 inch wide. I prefer 1.25 inches. Others may vary. Just be careful. Like metal, once removed and it is gone forever.
If you look around, I am pretty sure you can find a sawmill near you. Probably several that offer rough cut lumber of all species. Part of the fun is finding that magical piece. Lots of oak and walnut in your area. Probably cherry, and maple too.
From what you posted, that wood is pretty cheap. It does not give widths and lengths to tell for sure. Good luck in your search.
DeMo