Regarding this aspect of greed system: one of the benefits of being generous (= slower increse of World Greed) is smaller inflation in shops. It means you can eventually buy some very strong items that would be extremely expensive (= cannot be purchased even with all money you have) in the greedy scenario. So playing a generous style doesn't mean you can't carry a lot of gold, but that you are forced to get strong magical items from killed enemies or questgivers as rewards, and not from shops (your gold is worth little), for example. Having said that, since the game is in Early Access, all this requires a thorough balancing process (which is currently in progress).
NPCs not reacting when you empty their chests in many places seems to be a bug that will be fixed - thank you for the confirmation.
The game won't punish for looting, for a simple reason: when you pick up gold or an item you want to buy, the intention might not be greedy and it's impossible to distinguish this from a greedy intent. Not greedy intent: you want to use the gold to become stronger, for a greater goal etc. (and even to support the poor - so basically greedy vs. generous only depends whether you actually will use i.e. spend your reserves or will hoard them forever.) A more technical design decision, based on Zornilsa lore, could have been that any looting or possession of things makes Zornilsa stronger and thus increases world greed and chaos, but the RPG player community wouldn't tolerate it. Looting is a fundamental concept of RPGs and even the slightest impression (true or not) of being punished for it will infuriate thousands of players, except a very narrow niche.