The platforms are no problem. Every platform that I have built are still in great and safe condition. For the main supports of the platform, I drill through the trees and bolt on treated 4x4, 2x6 or better using 5/8" all-thread rod. Drill through, run the rod, crank the nuts, saw off excess, and then next hole. Lay the floor then the rails.

The Iron wood in Bancroft is way too thin for the 12 foot or higher platforms.

Thanks for the tips everyone. I think the 3 main things that I will do different for the ladders is:
1- Take the bark off the wood.
2- Use extra wood or something so that the ladder does not sit directly on the ground. Will add barrier between ladder and ground to reduce moisture absorption.
3A- Add in an angled cross brace to support the middle of the ladder.
-or-
3B- Stand the ladder almost vertical and strap it in the off seasons (Dec to Sept). Then pull it out at a good, safe, comfortable angle during the usable/needed months (Oct & Nov).

May have to incorporate some post-season work on top of the prime season hunt, pre-season work and off season dreaming.