Being an Australian, I don't like the idea of it being banned in Australia, so if adding child zombies means that it might be banned in Australia, please avoid it! That said, the idea of child zombies is good, so maybe if you still want to go ahead with it just make sure we can still get the game. Also though the idea of gear degradation would make it more realistic, I personally don't like the idea unless there is a viable way to repair said gear. For example degraded weapons could be repaired with scrap metal (maybe a tool, I've seen lots of suggestions for individual tools such as wrenches, hammers etc. so there could be a suitable tool for this as well.