Regarding the UI: I like the direction you're going, and I like how everything feels consistent between different menus. I have a couple suggestions, though.
The inventory squares being such a similar color and texture to everything around them is a bit much. Vanilla had darker inventory squares compared to the surrounding area in the UI. I liked that. The darker square kind of implied a hole or a recess that you were putting something in, and it provided a little contrast to split things up into different areas.
As for the troop recruitment list, there's a couple of particular things that would be nice. First, it'd be nice if you could filter the list by the categories at the top. So, if you clicked 'Veterans' or 'Peasants' or whatever, it would only show them in the list below. Another useful thing would be a checkbox at the top of the recruitment panel to 'Only show troop types currently in my army'. That would make it easier to grab the exact kind of troops you want once you have a few already in place. Finally, adding a little more contrast to the recruitment buttons would be nice so the colors between the faded out buttons, active buttons, and UI background isn't so similar.