it was thought the Mayans were cannibals because by 20th century farming yields, they couldn't have supported their population on the amount of land they were cultivating. However, they were using fish farming as the basis of their agriculture, with fish poop supplying nutrients for aquatic plants. This increased yields beyond any European level of dry farming. i'm guessing space colonies will employ similar techniques.
Windows for space applications are typically very thick. The ISS Cupola windows are 4 layers, separated by vacuum in between, 14.3 centimeters thick total, and with the inner and outer layers replaceable on-orbit. You could crash a car into that and it wouldn't do much.