I'm fine with complicated. I am tired of not having enough choices (most of the core 3.5 base classes are boring or overpowered) and would rather have decision paralysis than a cut and paste character.

I feel like a +15 to ac that can stack with other sources is a bit much. Even classes that offer modifier + 4, the usual progession, only amounts to 12 at the max and that requires a high number of ability score raises being put into one score. This is higher, has no cost, and stacks with armor. I would say 10 would be more reasonable or just the constitution modifier, all considered.

I haven't read through all of the paths, but the formation path looks incredibly interesting and nothing really caught my eye as being unbalanced.

I'm a little unclear with path restrictions. Do you choose one path and get stuck in it until one of the indicated levels? I'm tempted to say it would be better if you had access to all paths, but had to progress them in order (taking one from each path before you can advance to the next).