It makes no sense for the group not to take the vanquished poachers' weapons after the first ambush.
Lana mentions that when she was in grad school, "people said" she could be the next Aldo Leonard. She likely means Aldo Leopold, an American writer, ecologist, conservationist who is considered to be the father of wildlife ecology.
It makes no sense for those trapped by Krieger's system to light candles after Cerebrus locked them in and shut down the oxygen supply. The candles are burning up oxygen, so they would die even more quickly.