Constant Full Bank?
In the shop the top left most option in general settings will be 1 x Extra Bank Slot, you’ll need Coins/GP to purchase Bank Slots, it will also increase in price every purchase you buy it.
Gameplay Mode Restrictions on Purchasing Bank Slots
Normal & Adventure Mode has No LIMIT to the amount of Bank Slots may purchase, If playing on Hardcore, there is a LIMIT to how many Bank Slots you can purchase.
Selling Items in the Bank
You can sell items individually by clicking on them and selling them, on the right side panel, as long as they aren’t locked, you can Sell Them Individually or moving the Slider Bar on the right after selecting an item Changing the Quantity To Sell.
Sell All Option
There is a Sell All Unlocked Items in Tab option, while viewing a Bank Tab, there will be a Cog Wheel that is a Drop Down Menu with an Arrow on the right side just right of your Tab Value, this is where you can sell all in a particular tab of the bank.
Useful if you put items in a bank tab for junk, you can just sell them all without having to do them all one at a time.
Ignore Bank Full Setting
Only recommended if you know you don’t need any items you are crafting or collecting, but remains an option.
In the Settings, you can find it on your side bar, you’ll need to scroll down, navigate to General Settings, it will be the 4th Named Setting in the list, the top most option will be Ignore Bank Full, if you enable this, it will automatically destroy any item you are Gathering, Crafting or Collecting Loot from Monsters.