Jon,
FWIW, I downloaded both the new ADE and SAS for P3Dv4. I have both P3Dv3 and P3Dv4 installed on my computer, both running fine. I also already had the P3Dv3 versions of ADE and SAS installed and working fine for P3Dv3.
I installed ADE 1.75 Beta in a new separate folder, ran the Wizard, and it found everything fine and works fine. Then installed SAS 1.70 Beta in it's own new folder, selected P3Dv4 for it in the dropdown menu, and it runs fine with no error messages.
Both products worked fine "out of the box" for me, as they appear to do for you too. It doesn't seem to be a coding error in SAS or I assume I would have gotten the same errors reported above for at least SAS Beta.
Just my observations.