Einstein was a true theoretical physicist. I have no doubt that he would welcome challenges to his theories.
Absolutely! Beckman just offended the "settled science" Gorean crowd of the day. If I remember right, he admired Einstein, just disagreed with his TOR. He was aggressively pro-nuke in the '70s and of course, any anti-communist was trashed back then. This weenie is still bitter:
http://rationalwiki.org/wiki/Petr_Beckmann