Well if you're changing the other mers you might as well change Orcs to Orsimers.
They are very rarely referred to as Orismer, even the Orcs refer to themselves as Orcs.
Except orcs are rarely referred to as Orsimer
This.
I've always heard that Dwarf is simply the "Imperialized" version of Dwemer. So yes, it makes me wonder as well why it's called Dwarven in Skyrim as this is the home of the Nords that had contact with the Dwemer before joining the Empire.
It's obviously a small nitpick but I'd really like a mod like this.

Thats what I had heard as before to and I wondered the same thing, and thx

"Dwarf" was the name the giants gave to the Dwemer when they first encountered each other (at least that's the explanation MW gave for the odd name, since the Dwemer are a normal height in the lore). Over time, it likely just became the local term, picked up by the Nords from the giants, and later spread down to Cyrodiil, rather than the other way around.
That would make sense, thx Jiub!

I was thinking of also changing the Dragon priests name to Dovah Priest, thoughts?