Dunmer should still be able to summon an 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. 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.
Give Bosmer something called the Green Pact. If they consume meat or cannibalize someone they get 10% damage bonus and 10% 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.
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.
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.
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.
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 extendd duration to prolong its usefulness?
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?
Note. These are in addition or in direct replacement/modification of the current racials. If it was not mentioned it is left alone.
If anyone has any ideas or wishes to add on to or modify these just post below. I am interested in what people think.