Hi!
1. You can view the comments alongside the events that should explain how they work. Check the event template for the carrot. When the end of day switch is turned on, each template has its own page to add +1 to the <Self>Growth variable.
2. The <Self>Calculations switch gets turned off at the end of day calculations, like in 1.
3. You can change the page conditions on the carrot template event so that the variable needs to be 10 To be harvested instead of 3.
I'd advise reading through all the event comments and the setup instructions, and take a look at the video on the store page as well. :)