Einstein said he believed in the god of Spinoza, a pantheistic belief that says essentially that everything (in the universe) is god. There was apparrently some feeling of mystic serenity in feeling that we are part of nature.

I think many - possibly most - atheists feel this same thing, but they don't refer to it as god. Einstein may have believed in god, but the way in which he expressed his belief would include a great many atheists.
I don't know of many who would feel embarrassed by him. Confused, yes. Embarrassed - preposterous.