1. There are too many containers and so compulsive looters feel the need to waste a lot of time clicking on all of them.
2. The amount of money that exists within the game relative to the cost of the items you would wish to spend money on is not restrictive enough, which makes money feel worthless.
3. Every merchant is willing to buy every item. From a realism perspective this doesn't make a lot of sense. Why is the weapons merchant buying food.
4. Whenever you rest, merchants replenish their gold. This helps to greatly lower the value of money within the world by making it infinite.
5. It is too easy to pickpocket items off of merchants.
1. Lootable groups of containers rather than separate ones. I would say less loot as well but to avoid complaining then keep the amount the same
2. Money is really easy to come by, agree here
3. Different shop types might be harder to implement since it is often that vendors will die. Would suck to have killed off the weapon vendor in the druid camp and the potion vendor in the goblin camp and have only the food vendor in the Underdark left. Unless you mean multiple vendors in one location? Not really seeing a point for this and would make the map more cluttered.
4. Should take a bit longer than every rest.
5. There should be a merchant chest rather than bottomless inventory pockets. The chest should be in front of them as well, requiring more thought and creativity to steal from it. Chest should not replenish itself more than once a week, longer in some places and shorter in places along a trade route.