This isn’t really anything major, but I’d like to have an option to mark some of my limited items as “Not for trade”.
This would probably best as a setting on individual items rather than as a whole, because while I may not want to trade some items I have, I still might want to trade other ones.
I think this, and the opposite, are both good ideas. For example, if you are interested in trading an item it might indicate that and provide a link to the item listing. (I’m assuming that “interested in trading” can be set automatically by listing an item for sale)