It would be to our benefit to take a page out of the human's own book on diplomacy. When the humans wish to make treaties with another human kingdom, they send an individual empowered to make decisions on behalf of their respective governments: an ambassador. He usually is accompanied by his family and a staff of aides. I propose selecting an area outside the Mistwall, preferably in unoccupied territory, and gathering human and other races' ambassadors. By gathering them all in one place at the same time, we can not only guage their reaction to us, but their reactions to each other. A carefully-calculated campaign of information and disinformation should give us information we might need to consider opening trade relations. Let us say we are from far away, but drop hints that we live somewhere closer (but not in Antillia).
But I hear scoffing from the back room: why should the humans come to the middle of nowhere, even if they know we're fishing for information? Sirs and madams, the humans, like us, are very curious; why should they NOT want to know more about us? They have a saying which is applicable here: "If you build it, they will come." Of course, they will be learning about us the same as we learn about them. We should make certain to control our release of information carefully: do we open from a point of strength, or of calculated disinterest? What would the human ambassadors respond to better? If we opened with strength, then the humans might regard us as a threat.
These are the things we need to know. Who among the humans is a threat? Who can be an ally? Who has what we want? Who wants what we have? Who are our neighbors, and what are they like? What is their motivation? Without these answers, we have no clear strategy.
It does not take a majority to prevail ... but rather an irate, tireless minority, keen on setting brushfires of freedom in the minds of men. - attributed to Samuel Adams
“To preserve liberty, it is essential that the whole body of the people always possess arms and be taught alike, especially when young, how to use them.” - Richard Henry Lee