After the early game I never build any units that aren't mounted. I think that says it all regarding the lack of balance. most of the suggested changes here are excellent starts for changes. Horses make you fast and can carry heavy weights, they aren't magic and are quite expensive.
Great ideas IMO. The traits as they stand could use some work because there are a lot of no brainers, and it typically only makes sense to make generalists, which is a shame. Why make anything other than strong fast mounted tanks with awesome weapons?
I loved Impulse and love Steam, and steam is always the first place I look for games. It offers me many services I value, particularly not having to have 50 different accounts for everything and being able to view my library at a glance. Honestly if a game isn't on Impulse or Steam there is a 99% chance I will not buy it. In the past 3 years I have probably bought 100-150 games on Impulse and Steam, I have bought 3 that were not (SC2, D3, and Distant Worlds).