Avoiding A Full Inventory:

Complete the quest to obtain the three Teleport Stones. You can now create a system where your inventory will never be full to the point that you will miss valuable treasure. Leave one of the three stones in Tharbakin. Whenever your inventory gets full, throw down a second stone and teleport back to Tharbakin. Go to a nearby merchant, sell your unwanted items, then teleport back to your previous location.