SnowDog1942
Navezgane's Perv
Perhaps the player who doesnt want to shoot anything should play on carebear difficulty.You may not be able to design around it but it should be kept in mind when balancing. A well designed base should be able to take care of the first few hordes with minimal help from the player. That should be the extreme edge of a builder character, one who doesn't particularly want to shoot anything, otherwise there's little point in getting construction perks when combat perks are a necessity.
Unmanned defences may not work in real life but as we are repeatedly told, this is a game not real life.