Basic trade route question

Yes. Go to the Trade-tab in the Finance Management screen, select one of your trade routes, and then click on Kill Route.

Yes. Under the domestics window (the thing you select when you want to adjust spendings and tax rate), you should be able to find a tab called trade. With that tab, you can get information regarding individual trade routes and be able to kill it if it displeases you.

Edit: I think I got ninja'd (correct word?) by 8 seconds.

Thanks.