By placing on the board, I mean having the upgrades for cursor, miner, dice etc. as buildings of some sort, so you don't need to have a sidebar on the right. I don't know. It feels like if you are going for a monitor as the design the sidebar seems a bit out of place. And you already have different icons on screen anyway, so I feel like they can be combined together? Just random thoughts :)
And I am not aware that you can upgrade the archer to a mage cat or a crossbow cat. It already sounds cute without even seeing them. For my playthrough, I mainly focus on economy and quantity. By making the path as bad as possible for the enemies, I don't think I need to upgrade any cats to level 10. It's a shame I don't get the chance to see cute mage cat :)