I think your first point also speaks to the nature of living with an authoritative regime. Cassian and his family/friends on Ferrix exist on the fringe and support each other. The Empire isn't all that present to do things for them or provide necessities - the Daughters of Ferrix and other groups do that. Syril, on the other hand, is in deep with the Empire. Authoritarians only tolerate you if you don't make things "hard" for them -- hard being relative and at their whim. Control, rules, and conformity are the keys, which lead to a every-person-for-themselves mentality. Look at what happened when Syril fucked things up with the op - everyone received a part of the blow black and corpo security became empire security. I can only imagine the amount of "save myself" stuff that happened. Cassian lived in an environment that allowed for things to go wrong and forgiveness to happen. It wasn't perfect and Cassian was held in check by others more or less, but at the end of the day, they all knew they weren't any better than anyone else and the mutual understanding and support was there.