Just food for thought, but could the lack of contact/thieves/ambushes/sieges be due to the fact that kobold sites are hidden and don't appear on the map? Don't know much about it, but the in fort I'm playing now the humans and goblins don't seem to know about my existence yet. I got spring caravans from the elves but I think that's due to another edit I've made somewhere else, not sure if its part of the mod as I was under the impression that all other civs would be hostile... (no matter, slaughter enough merchants and they'll attack like everyone else. I think maybe they got upset when I stole their giant skunk.)
Started in year 5, around the end of year 7 the elves ambushed. (They got poor Gaykus, my legendary miner. Took all 6 of them to get past his masterful pick-axe skills, he died a hero's death. Held them at the surface long enough for my military to get organized and engage, saved many lives...) Anywho, haven't heard from the elves since, I think the goblins are giving them a hard time. Scouts sent to investigate are finding a lot of abandoned sites. Good chance they're gonna die out.
One odd thing I've noticed is that none of the kobold caravans that come have any goods with them. They still accept offerings though so i can keep raising my exported wealth. (this may be something I've done wrong while integrating the mod with my raws. Just wondering if anyone knew how to fix this.)
I'm going to try and raid a smaller goblin pit nearby, see if I can't alert them to my presence. I'll let you know how that works!