Luna does have Sableye. Also, Florinia has Ferrothorn at Fiore Mansion. (also if you're going to include Sun/Moon Pokemon it might be best to include a spoiler warning in the thread title)
Julia: Oricorio Pom Pom Style
Florinia: Chesnaught. Spiky moves in desert.
Corey: Salandit. Corrosion. Corrosive Field. Corey's name pun is corrode.
Shelly: Cutiefly
Shade: Dusknoir for reasons you listed, or Cofagrigus because of the eyes
Kiki: Mienshao
Aya: Scolipede
Serra: Alolan Ninetales
Noel: Drampa
Radomus: Alakazam
Luna: Absol. One belief Luna mentions a lot is that darkness is misunderstood. So is Absol. People think Absol cause natural disasters because they appear when they're about to happen, when Absol is actually trying to warn people.
Samson: Machamp.
Charlotte: Alolan Marowak
Terra: Dugtrio
Ciel: Crobat. You can't spell acrobat without Crobat.
Cal: Camerupt.
Blake: Cloyster (was actually his ace for a league season)
Bennett: Beautifly or Mothim are the only two butterflies/moths he hasn't used
Sigmund: Magnezone.
Victoria: Pangoro
Cain: Roserade
Fern: Amoonguss
"gender neutral"
"he"
Adrienn's pronoun is xe.
(not trying to be rude so sorry if it comes out that way, just noticed that it was acknowledged Adrienn is gender neutral while at the same time "he" was used to refer to xem)
The similarities between Titania and Erza are coincidental, and it drives Ame up the wall how similar they are.
Anyway, welcome to Reborn! Here's an ice cream sandwich
The badge is still in your case in the trainer card. It doesn't exist but it does at the same time. Tristan's badge raised the cap to 50 despite supposedly not being there, so I don't think we have to worry about his badge effecting the level cap.
(it's also possible we grabbed one of the badges from his house when we go there)
It's in the house with the door where the guy says he's never been able to open it. You need 2 keys to unlock it. One of them is in a cave near the top of Silver Rise that's inaccessible during your first visit with Tristan (it's near the staircase that goes to/from the peak) and the other is in Shade Forest. In Shade Forest, there's an ice pyramid with a staircase being blocked by some boulders. You need to go around activating crystals (same as in Silver Rise) until everything in the way has been removed and you can go down the staircase. There's also a catchable level 45 Froslass down there.
I haven't played 3.1 so I don't know if her team changed along with the new ship scene, but in the original release of episode 3 she had Crobat, Cacturne, Milotic, Blaziken, Zangoose, and another Pokemon that I don't remember but it wasn't Nidoking.
If you gave Cera the Magma Stone, you need to go to the other entrance to Valor Mountain which is in Crawli's gym (past the door he enters through when he battles you on the bottom floor).
I didn't know the hooded guy who battled Heather was Corey, since I didn't find all 5 police officers (I missed the remains of the one in the library by not knowing you could walk on the bookcases). I thought he was an admin.
I remember someone asking once if there were going to be Gym Leader rematches (I think it was in the "We make Pokemon Reborn. Ask us anything" thread) and Ame said it wouldn't be much of a postgame if you couldn't.