I Was A Teenage Exocolonist: Perfect Ending Guide (Years 17-19)

Hello and Welcome Everyone! I love Exocolonist, it's one of my favorite games, which meant of course I tried to get the best ending possible, but I could only find one guide for it which left out important events and strategies. So I made my own!
This part goes over the third stage; the adult stage, of the game. The first stage with ages 10-13 is here: • I Was A Teenage Exocol... and the second stage with ages 14-16 is here: • I Was A Teenage Exocol...