Dunmer should still be able to summon a Flaming Ancestral Ghost. For me I like to RP chatting with my Ancestors sometimes. Not really but I liked to think I could. Plus a decently powerful leveled summon would be a nice addition to their powers that we have seen in the lore. Think of it as the more powerful you become the more powerful the ancestral ghost who answers your call. Like maybe every 10-20 levels and an up in power? Familar power, then flame, frost, and shock atronach, finally Dremora lord. Make it last very long as well as it is a power. Like 180-300 seconds or 3-5 minutes. Eventually making it a bound summon. Also Sul did it after the Red Year in the novels so their is 'hard' evidence of it being lore friendly.

Give Nords a small shock resistance like 25% alongside the 50% frost and the ability to do a grab that freezes an opponent. Like the power they had in Oblivion. Frost damage on touch. Just make it like Ice Form instead of pure frost damage. Freezes the opponent and deals slow frost damage over time.

Give Argonians resistance to poison again. Like 75%. They live in a friggin swamp! Constant water breathing effect. They also should swim about 50% faster. Make their histskin power regenerate health and restore all health the first time it is used.

Give Bosmer something called the Green Pact. If they consume meat or cannibalize someone they get 20% damage bonus and 20% damage reduction for everything for 300 seconds. If they kill something and do not eat it they do not get the damage part of this bonus for 24 hours no matter what they eat, unless they eat it. The rest of their traits are good.

Altmer should have disease resistance again. Makes sense. They breed to make superior specimens. Make increased magicka regen permanent by 50%. Have them take 25% more damage from the elements again and give them a power that lets them have an unlimited magicka pool for a 30-60 second period once a day to show their attunement with magicka. Also a magicka bonus of 50 points as well.

Redguard's Adrenaline rush should give a temporary 50% boost to melee damage of any kind for 60 seconds and they have unlimited stamina during that time. Can be used once a day. 50% disease and poison resistance.
They also run a little faster and jump a little higher than the other races. To better represent the Athletics and Acrobatics they had in previous games.

Give Orcs a small magicka resistance again like in Oblivion they had 25% resistance to it. Call it a trait of their merrish blood despite their cursed state. Keep Berserk the way it is. Small boost of 50 points to carrying capacity as they are the physically strongest race.

Khajiits should get the Eye of Fear power back, the one that causes all those around them to flee in fear. Also a power that lets them pick pockets and locks more easily when on Skooma or moon sugar...or a once a simple day usage lol. They also run a little faster and jump a little higher than the other races. Keep the base unarmed damage bonus and increase swing speed of unarmed attacks by 20%

Bretons should have 50% magicka resistance again. Also a smaller yet still decent boost to magicka. 30? The spell absorption power they have is pretty good, maybe extend duration to prolong its usefulness? Give them a trait called Dragonskin that boost there damage reduction by 20% when their health is below 30%.

Imperials should get the ability to charm all those around them for a brief time. Up to an appropriate level. Not too sure what else. Chance to find better items as well as gold in the Imperial Luck power? Imperials are very plain and I feel like anything outlandish would be lore breaking. Maybe increased companion health and damage dealing? Give them a trait called Imperial Tradition. Buffs all skills up to 10 points and lasts for 300 seconds.

If possible this could be accomplished rather simply I think. It could also make it cooler imo. Have each leveled ghost appear different. Use the Ghost NPC look, retexure it with the flaming familiars texture, and just add weapons and armor to them. Keep it with a Dunmer feel though if at all possible. So far the closest thing to actual Dunmer looking armor is the falmer armor sans the helmet(shudders). Just use apparel to make the ghost look unique. Leave their heads bare so we can tell it is a mer under there. You do not have to make the armor appear on the ghosts in the same strength that they do in the game. By this I mean Ebony armored Dunmer ghost can be weaker than the Falmer armored one. The Falmer armored one harkens back to the old days of legendary Dunmer heroes or some such. You could have the list like this.

Remember Helmet-less for appearance's sake. However appearance is subjective the armor and weapon descriptions are merely for appearance sake and are what I think is appropriate. If someone thinks different speak up. I have not seen all the weapons and armor in this game yet. Not even close I think.

-Summon Ancestral Ghost-Regular every day Dunmer ghost in clothing with no spells and iron weapons including a bow. Presumably one of your less auspicious ancestors, that was a merchant or farmer. Level 1-10.

-Summon Ancestral Warrior- Dunmer in a regular armor set. Fur, Leather, Iron, Steel. Has Steel weapons or maybe Orsish. Weak level spells like flames, sparks, firebolt and lightning bolts. Presumably one of your tougher yet unknown ancestors. Level 11-20,

-Summon Ancestral Guardian- Dunmer in a set of Elven, Orcish or Glass armors. Likewise weapons. Stronger spells. Presumably an Ancestor that was accomplished and respected, yet forgotten throughout history. Level 21-30.

-Summon Ancestral Hero- In Ebony armor and weapons (lets reserve Daedric for the Dremora). Strong spells. An ancestor who did much and is fondly remembered as a source of great pride and prestige in your house, whether or not you know of your ancestral lineage or not. Level 31-40

-Summon Ancestral Myth/Legend- In Falmer Armor, not the helmet. Whatever armor you think is appropriate. Daedric Longsword. Powerful spells. Like master level Destruction and Illusion spells. An ancestor so powerful that they only answer the calls of those in their family with power to match their own. Little is known of them but their deeds in the early wars against the Dwemer and Nords in the far distant past guaranteed the success of many battles against their ancient foes. They are an ancient and powerful spirit capable of changing the course of any battle. As strong as Dremora Lords if not slightly more powerful. Level 41+.

At level 50 you gain the ability to summon and banish them as a permanently bound summon.

Something like that. It is rough but there it is. Of course equal attention would need to go towards the other races I think for balance lol. How anyone accomplishes that is their own business.