"Recruiters for Immigration and Customs Enforcement and the U.S. Border Patrol were on hand, along with an armored tactical vehicle they drove into the exhibition hall."
The thorn symbol was used as a letter in medieval English. The sound produced when read aloud was "th" as in "thus" (corresponding to the greek letter δ). To the best of my knowledge, it did not produce the sound "th" as in "think" (corresponding to the greek letter θ).
DS9 does have such an episode. In "Rejoined", Jadzia Dax meets Lerana Kahn and it is revealed that their past symbiotes were married to each other. Their love to each other still lingers, despite the fact that they are both female now.
