When you select a house, the UI panel on the left tells you what it is going to do (rest, tend grass, tend trees, create medicine, etc.). No visual indicator yet, but I'd like to get that in for the next update. Which parts did you find ran slow? Although you're absolutely right, parts of the code definitely need to be rewritten to be performant, I imagine Unity's Garbage Collector is working basically constantly.
Thanks for playing, and thanks for the feedback!