Hopefully the devs see your post, it's well thought out! Just wanted to offer my two cents on certain points:
#2 - one of the reasons I appreciate (and wish there were a more flexible system for specifying more requisites to upgrade aside from money and a choice item) the current system is that it takes into account post-battle looting. Recovering horses from a battle is generally how I upgrade my cavalry, not by purchasing them in a town. I would like the same to be applied to armor and arms, but then there's the complexity of specifying which weapons qualify for specific unit types, and that all seems unnecessary given their other priorities. It's always been strange that upgrade costs are so low relative to the market price of new equipment, though.
#3 - Nobles should generally not be found in towns, largely because towns are where the free commoners and burghers live, not the nobles. Being that this is based on the High Medieval period, most lords owned manors and castles in the countryside, so it makes sense for the more elite troops that would presumably form their retinue be found there.
