Some Clarification
The City is loosely ruled by a Council made up of the heads of the five Clans <Hurdrinn,Valkorim,Grentregh,Bremdarull and Temperlain>.
Prince Alembregh Temperlain is the de facto spokesman of Temperlain, so an appearance might be good. From what Terrick knows, Grentrigh currently has no real ruler, only a Marshall elected by the survivors of the Clan.
The Orc Lair that you raided was perhaps 3 miles of real distance away, with no direct connection as far as tunnels go, at least none that the dwarves had dug <on the maps>.
As far as close <known> enemies accessable via tunnels, there are three
Enemy footholds withing striking distance that the Svirfneblin knows of.
One
A Drow outpost lies perhaps a mile away, along an old access tunnel leading to the Silver mines to the West. Estimate of Strengh is maybe 50 or so Dark Elves, although they are sure to have many slaves and other allies.
Two
A Duergar Stronghold has been established in an old Guard Station. Numbers are hard to tell, although there have been sightings of at least 30 Grey Dwarves at a time. These have Hobgoblins in their service as well, perhaps 50 of them.
Clan Bremdarull is closest to them and keeps a strong vigil.
Three
On the shores of a subterranean Lake south, there have been many Dwarves lost to something lairing in the waters. Kuo-Toa have been encountered, but suspicions abound that something darker and more powerful drives them.
As well, the Orcs <not the same Clan that you raided> that had attacked on a raiding mission when you first came to the City had dug a tunnel in. You could go and ask about findings regarding that, and perhaps mount a counter mission, although Alembregh knows that Hurdrinn was doing so when you all went through the Portal.
Clan Valkorim will most likely already be spreading the word that you recsued Kendragi and the human, as well as brought back loot (and a Giant head, Duranom grabbed it

).