Am I sinful for discarding dry food against my will, and for discarding my neighbor's unclean food that I cannot eat for fear of offending her?

Food is a resource that should not be wasted. If surplus food is received as a gift, it is preferable to seek out needy individuals among the poor or workers to give it to. If no one is found, it should be given to animals to eat, and it should not be thrown away directly unless there is a fear of harm from it.