JB I'm not sure I have the right picture in my mind of what you are doing but it sounds like serious overkill. I built a tree stand for our archery club about 20 years ago. It is 8' off the ground and 2 people can stand and shoot from the platform at a time. 4 people can easily fit as long as they aren't drawing bows back. The ladder is a pair of D fir 2 x 6 with 2 x 4s for rungs. The 2 x 4s are on edge. I can't remember how wide I made the ladder but maybe 4' wide. The rungs are fully set into the stringers which aren't quite straight up. Maybe a 10 degree angle. I couldn't tell you how many people have been up and down that tree stand since I made it. Hundreds for sure. It's just now getting to where it may need some refurbishing. That's after 20 years but with a good coat of outdoor stain on it. It's not in the sun so that helped.