Rather than a whole-sale "Block Trades", it would be night to block trade requests for SPECIFIC Commodities and Resources....
i.e. If I'm willing to trade, but I'm not willing to give my Grain up under any circumstances (the barbarians are 2 away, and I don't have an active knight on the board - I ~need~ it), I ought to be able to "Block Trades" requesting that one thing, but still entertain offers on other Commodities and Resources.
If I'm not willing to give up grain, it's annoying to get 6 offers for grain before it's my turn again. no, no, no, no, no, no, no, but I can't "block trades" because I want to trade OTHER THINGS.
On that screen where the 8 columns of sliders exist... It would kick ass to put a "block trades" check box under EACH of the 8 Commodities and Resources.
...But I'd still want a whole-sale "Block Trades" box that turns on ALL EIGHT... And turning that "master" checkbox off would clear ALL EIGHT individual checkboxes.