Yes I know about his sister's envolvement, I took an entire philosophy class on him.
Obviously, he wasn't actually a "Nazi" since he predated the movement by nearly a century, but his work certainly influenced Nazi ideals. I guess one of the biggest differences between his ideology and Nazism's is that instead of killing off the jews and other "undesirable classes/races" he would have put them all to slave labor (which the Nazis did to some extent).
And it's historical fact that he was often sick and eventually went insane.
And Einstein was a deist, that's it.