There’s not religion in Arda, per se, there’s just Eru and the Valar.

He would have to be old almost beyond reckoning since Morgoth corrupted and twisted kidnapped Elves into Orcs before the rest of the Valar even realized the Elves had awakened

Sure, but there’s also the Sinking of Beleriand.

Adar’s got a pretty good idea of where Arondir’s people live(d).

In the Akallabeth, at least, the Palantiri are merely named among the heirlooms of the Faithful

Sure, and that’s my point. The only way (prior to this episode) we’re told there are seven Palantiri is in terms of what survived Numenor.

I can’t see that as being possible. The show has to roughly follow the story and Sauron never left ME and started raising an orc army out of Mordor, which we are currently seeing.

Aule was also named in one of the first scenes with Durin.

2) in part bc the Silmarillion says that nobody lives at the mouth of the Sirion, that Arondir misspoke;

I find it most believable to assume that Adar is an extremely old Elf who was one of those captured by Morgoth to breed the race of orcs into being; hence, he’s their Father, as the name implies, and that’s what gives him such respect among them. They owe their existence to him, and maybe he has promised to improve…

The palantiri, for instance, were innumerable until Elendil brings seven stones with him to Middle-Earth.

There’s a few physically imperfect but virtuous characters in The Children of Húrin, like Labadal, the crippled servant, or Brandir, the lame healer. 

The person sending signals could get them from a computer program. And these days computers can usually beat even the best grandmasters. 

Its also worth remembering that the show doesn’t have the rights to the Silmarillion, so anything expanded out in that or Unfinished Tales is, with a few negotiated exceptions, likely going to have to be changed or not follow the same path.

I believe it was already confirmed that the Balrog we see in the LOTR trilogy is the same Balrog we see in the trailer.

He said in this episode that he’s from Beleriand, though that doesn’t narrow things down much. He could be a Sinda, or a Nandorin elf, or even mixed heritage. I would guess Nandor, but that’s based on nothing more than a feeling. 

Círdan definitely, and there’s some other possible candidates with vaguely defined ages, like Amroth or Oropher. I’m not sure if Tolkien even decided whether Fëanor’s grandchildren had still been around in Valinor, or if they were only born in Middle-Earth. 

weren’t all of them human kings and ringbearers who got corrupted by Sauron’s magic through their rings?

- Theo is a potential candidate for Mouth Of Sauron.

For all the complaints about the show disrespecting Tolkien’s lore, I felt that this episode was almost bogged down with the lore explanations, vital to understand the characters’ motivations, but occasionally so dense that they brought the action and character moments down to a halt. I hope that casual viewers manage…