Not really, in the Blood Wood even before the ritual of thorns she would coerce her former lovers into committing suicide,
Hm, I don't remember that. Maybe you have quote?
her arrogance with her superiority led directly to the mess that required the thorns. She wouldn't even entertain the idea of another way of surviving even though her advisers tried telling her that a wooden kaer wouldn't work, it was the "elven" way.
I don't think Alachia's believe in the superiority of elvenkind was the point. She did not want to accept Theran rule, probably out of some combination of rivalry with the Theran immortal elves and wanting to keep her personal power. And the solution they found did work for 200 years, so I don't think its eventual failure even though suspected by some was a forgone conclusion that Alachia chose to ignore.
Anyway national socialist ideology can be hardly called innovative. A believe in the superiority of your tribe, nation or race is almost the oldest thing there is. So I don't feel the time of Alachia's rule is particularly close to it. Now some of the stuff in
Worlds without End could be a different matter. See below.
The reason i went with Eva Braun is because..1) Alachia would not be happy just being the girlfriend of some mid level Nazi, she goes for the top everytime and 2) her physical description could easily fit with Eva Braun and yes she isn't named as Eva Braun, but Aina strongly implies that she is very very close to the power in Nazi germany. Anyway the various scenes are of course supposed to show that Alachia is drawn to temporal power if not addicted to it and that she has very Little in the way of a moral Compass or at least a moral Compass very unlike anything we would recognize as normal, contrasted to Aina WHO has no interest in temporal power and a very strong moral Compass.
I agree in so far, as the scene works on guilt by association. Look who she pals around with! And it's unlikely there is a mitigating factor. Caroline Spector probably didn't think to herself, this looks really bad, but what Aina doesn't know Alachia is actually an allied spy!

Still we don't really know what Alachia wanted out of the Nazis. For the purpose of the book it should probably be seen in light of what she told Aina before:
We can control what happens over the next thousand years. Make the world over in our image. Think of it—the power will come back again. Not this trickle, but a deluge of energy to rip loose the moorings of the world—unless we make certain of the proper order of things. Humans are sheep. We will always rule them.
The legends and tales you strew about aren't enough. We must have more. We must control them. This is our destiny.
But what does that mean for her plans at the time? So I don't know it served her ambitions to hang out at Obersalzberg half of the time.

On the physical appearance: red hair and legendary beauty? Don't quite see the fit with Eva Braun.
And just wanted to add:
Braun would not have been publicly affectionate in this way with someone besides Hitler
Even that would have been frowned upon, as the relationship wasn't officially acknowledged. But I'm pretty sure that didn't give her leeway to pursue another public relationship on the side.
We've been able to retcon and play with a few things. but there's no way in Hell that anyone involved with Shadowrun would deny the people truly responsible for the Third Reich agency for being some of history's greatest villains. Just like whatever else happened in WWE, there's no way Alachia was actually Queen Elizabeth I.
I don't mind it in the latter case. Aina's reaction in
Worlds without End implies that the move was either frowned upon or thought to be foolish. So I see it more as an exception to the rule. As for appearance in this case, I just want to point out Cate Blanchett played both Elizabeth and an elven noblewoman. Coincidence?

In general, posing as a famous person probably becomes tedious if you have to set it up again and again. It could also expose you to your rivals.
Another reason why I'm surprised no one has offed her yet. Alachia actually killed all of those advisers and banished their children from the Blood Wood. One of those children was none other than Aina, who then fell in with a Nethermancer, and then accidentally caught Yrsgrathe's eye. I think we all know what happened after that.
So, in effect, every bad thing that happened to Aina is Alachia's fault.
There are various versions of the story of how Alachia rejected the Theran offer in the Earthdawn sources. There are certainly several inconsistencies with Scars. As I said before Alachia isn't portrayed as really evil in the other sources.
The Blood Wood mentions banishing of advisors but I think even the history on the "Iron Queen" Liara does not mention summary executions for disagreement. So yes, the single-minded villainy and pettiness Alachia displays in the Immortals (Aina) trilogy doesn't quite work with her successful manipulation of other people and continued good standing among the immortals which even the trilogy acknowledges in a number of instances and through the ages.