The title is a play on the wedding rhyme/tradition, dating back to 19th Century England, of the bride wearing “something old, something new, something borrowed, something blue (and a sixpence in her shoe),” for good luck. The green, of course, refers to the pigmentation of Orions.
The ship seems to be a new class of Orion Interceptor with some extra added bits, the original design of which dates back to the 22nd Century (ENT: “Borderland”). The female Orion plays with a TOS style phaser pistol and then tosses it in the trash. They talk about body modification, specifically “bolts in the head”, which we saw on the Orion privateer Harrad-Sar (ENT: “Bound”).
Mariner calls Tendi “D”, which is a reminder that her full name is D’vana Tendi. Tendi refers to Orion “belly dancer outfits” (TOS: “The Cage”, “Whom Gods Destroy”, ENT: “Bound”). Mariner says she has put her foot in her mouth about Orion culture enough times (LD: “Crisis Point”, and Boimler did the same in SNW: “Those Old Scientists”, when both assumed all Orions were pirates).
This is the first time we’ve heard of Andorian linen, but Andorian silk was also prized as a fabric (DS9: “Q-Less”). On the shelves we see Boimler’s plate of the Cerritos, his figures of Mirror Archer, Spock in his monster maroons and Data holding a phaser rifle (LD: “I Have No Bones and I Must Flee”) and his “Boimler Effect” plaque (LD: “Temporal Edict”). On Rutherford’s side we see his DS9 model (and box) from LD: “Hear All, Trust Nothing” and a replica of Wesley Crusher’s tractor beam emitter model from TNG: “The Naked Now” (also seen in “I Have No Bones…”)
Grandmama Boimler said, “A cool duvet keeps the raisin rats away.” The Boimler family owns a raisin vineyard on Earth (LD: “Grounded”). “Lil Boney” the bonsai belongs to Boimler, who acquired it reluctantly in LD: “We’ll Always Have Tom Paris”.
As the Yosemite II shuttle approaches Orion, we see a space station in orbit and also an Orion barge, resembling that piloted by Harrad-Sar in “Bound”. In Star Trek Online the 25th Century version is known as a Blackguard-class Flight Deck Assault Cruiser. We see an Orion riding a purple rhino with two horns and two tusks.
Mariner references Chief Engineer Billups’ background as a prince of Hysperia when she remarks that Tendi also grew up in a castle (LD: “Where Pleasant Fountains Lie”).
One of Tendi’s titles is “Mistress of the Winter Constellations” (“We’ll Always Have Tom Paris”). We learn that Tendi’s parents are the Warrior Queen Shona and B’Rt. Harrad-Sar alleged in “Bound” that while most of the galaxy harbors the misconception that Orion women are slaves, it is actually the females who dominate the males via their pheromones.
Symbolic bridal kidnappings (as opposed to actual ones, which are considered sex crimes) are still part of some cultures on Earth. In the case of Orions, the kidnapping is done by a rival family between the save the date and the issuing of the invitations. Tendi is Prime Daughter.
The real Samuel Clemens (a.k.a. Mark Twain) appeared in TNG: “Time’s Arrow”.
Comparing the lettering with the name of the bar (“Slit Throat”), the Orion alphabet is a straight one-for-one substitution with English (like Gorn script in SNW).
New Seattle is located on Penthara IV (TNG: “A Matter of Time”).
T’Lyn observes the Orion males in the “scentuary” are under the influence of chemicals, possibly pheromones. Mariner claims that Starfleet made that up to explain why a starship captain could be taken down by “show girls”, referring to the events of “Bound”, but is proven wrong. Tendi clarifies that only some Orions control others through pheromones, but not her. Ingreeta later claims Tendi doesn’t have the pheromones (but didn’t need it).
Coqqor is a Chalnoth (TNG: “Allegiance”) and claims to be from South Chalnoth, although the name of the planet is Chalna. Coqqor could be referring to a region or a city on Chalna.
The ship that Tendi says was one her and D’Erika’s favorites appears to be of the same class as the SS Raven owned by Seven of Nine’s family (VOY: “The Raven”). Tendi was raised as a Syndicate assassin, a “prime”, to be the Tip of the Moonlit Blade.
If we’re keeping score, I think Mariner gets stabbed four times in the shoulder (at the Slit Throat, the scentuary, by D’Erika and at the daughter-daddy dagger dance).
While Mozart has never appeared on Star Trek, many of his works have been heard over the course of the series in episodes.
I'm pretty sure an actor appeared in Time's Arrow