I'm a big fan of shovels as a melee weapon. A twisted minded person would sharpen the blade so it becomes a really wicked ranged edged weapon.
Sid, did you know you can go over to Amazon and build a Zombie survival list? Supplies, weapons, equipment, clothes... with comments. Kinda fun when you have the time.
Anyway, the colony is basically an enclave in enemy occupied land. Everyone should be carrying something for protection. The fact that they aren't points to Marcus losing sight of real problem.
Yes, we humans are basically lazy and selfish. Given the choice a majority of the people would choose not to work... BUT, if you cultivate a culture of hard work and communal integrity, you'll get people to put in the time. The whole Serf thing is too heavy handed.