Whether or not we keep the story that the Petty-Dwarves ambushed and attacked lone Sindar for no apparent reason, resulting in the Sindar mistaking them for maneating animals and hunting them, I do think that story is indicative of what these people are like. Oh, immigrants. Let's murder them! With no warning or attempt to explain our grievances!
i) Question: Do we want to stick with depicting female dwarves with beards, which is admittedly a central part of their making, at the risk of horribly confusing the audience?
It's confusing to Elves and Mortals, too. So yes, keep it!
i) I imagine that we'll mostly see the Longbeards, given their prominent role in the story and their location in Beleriand.
The Longbeards live in the Misty Mountains. The Broadbeams and Firebeards are the Blue Mountains Dwarves.
D) All dwarves should originally be illiterate. They adopt systems of writing after encountering the Elves, and they refuse to use the newfangled Feanorean runes once they come over from Valinor. Thus, Dwarven art and architecture should include no inscriptions.
They actually did have their own ideographical writing system before they learned Elvish writing systems. They used it only for Khuzdul, so they kept it secret, and decided that Daeron's cirth are more useful for anything that outsiders might see. By the time they saw Feanorian tengwar I guess they'd just gotten used to cirth and preferred them, although we do see Ori and Thorin, for example, use tengwar in the Third Age.
C) I dislike the idea of "Mim the Deathless". The "once and future king" aspect is what marks Durin as unique. Spreading this out to Mim and possibly other dwarves renders Durin's uniqueness less culturally valuable.
I agree completely. The Seven Kindreds each have a Father who is supposed to be reborn in his descendants, or something like that. But the Petty-Dwarves aren't a Kindred with a Father made by Aule. Mim wasn't the Father, he was just the father of the last family of his people. And none of his sons was named Mim.
I do believe that, with the idea that Dwarves do not reveal their true personal names to outsiders, that it has to be assumed that Azaghal is a title instead of a personal name. Could it be simply the Khuzdul word for King or Father? At
http://folk.uib.no/hnohf/khuzdul.htm neither meaning has an attested Khuzdul word, although uzbad is 'Lord'.
C) To Elvish eyes, dwarves will also be very unlovely, and they should wonder whether the dwarves are also bad guys. Have the question asked, "Is the enemy of my Enemy my friend?"
They meet the Dwarves before the Orcs, but they are probably wary and curious at first. After all, there were monsters at Kuivienen, and probably nobody got a good look at them in the dark... But they quickly figure out that trade and alliance is super useful to both.
1) As far as I can tell, the racial enmity between Elf and Dwarf seems to be universal, and nobody argues about who killed whom.
This is not true. The Eldar (mostly the Sindar and Nandor) and the Dwarves of Nogrod became enemies only because the Dwarves murdered Thingol and sacked Doriath. Before then they were allies. People like Celeborn and Thranduil got racist about it and decided to mistreat the Dwarves of Belegost and the Longbeards, who had nothing whatsoever to do with that war. The Noldor and Longbeards became very great friends and allies, until Sauron destroyed Eregion and the Balrog drove the Longbeards from Khazad-Dum. The Avari and the other Kindreds had their own relationships based on whatever history they had.
Where are the names of the other dwarf families coming from? Everyone seems to know what these are and where they're coming from. I see them on the tolkiengateway wiki, but I don't remember them from the text.
"Of Dwarves and Men" in Peoples of Middle-earth, vol 12 of The History of Middle-earth. It was written 1969 or later. The Seven Kindreds are Broadbeams and Firebeards (Blue Mountains), Longbeards (Gundabad and Misty Mountains), Ironfists and Stiffbeards (further east), and Blacklocks and Stonefoots (really really far east).