Hi!
Well, if you don't have any hunters, you will have a short period of peace - until the caravans come.
I think I didn't get to the elven caravans in my worst unicorn map, or at least, I don't remember them there.
The human caravan usually kills off a handful of the unicorns. On occasion, one or two members of the human caravan will die, but usually the swordsman are tough enough to finish what they start, so nothing to worry about (most of the time).
The dwarven caravan is weak. Really weak. And the unicorns I had were really nasty. They would always meet with the dwarven caravan when they left, killing half the caravan. The axedwarves are completely useless, so there are lots of bloodthirsty would-be horses waiting for your dwarves to come to collect the murdered caravan members' equipment/bodies.
Engravings of unicorns killing dwarves were the one most common engraving I had in such regions...
My recommendation would be temperate, calm, with lots of vegetation. Unicorns only haunt the extreme benign (?) areas, and elephants are only in the warmer climates. So the worst you will have are cougars and wolves for predators (no problem for the caravans, and only dangerous for hunters), and rhesus macaques and racoons for item stealing and job disruption.
Deathworks