You can also discard trading goods and supplies in the Goods window.
Yes I think about this too late. I had bought some goods, if I could sell them somewhere. So I will no longer buy some, it's too dangerous (seriously, lol), and I destroyed about 5.000 gold of loot for a possible sell of goods for a 100 golds beneficial.
So maybe they should be put in a special bag in the main inventory tabs, to the right end of the bags, or maybe to the very first tab, to the left of the usual one, so we think about them more easily.
It makes me think about a possible bug:
I can't make goods quests because it says it overload my group, but my load seem to say I could take the quest.