Hi !
First of all, thank you SO MUCH for recording your stream and give such a thoughtful review. It was super interesting to watch.
For the issues you highlighted:
Technically you did have more minions when you bought the upgrade (or they spawned faster), but the buttons above control the waves of minions, which is misleading I agree.
The wallnut one is a sheild that increases your defense stat hahaha
Thanks again for playing, commenting, and streaming the game, this is so very nice of you ❤❤❤