For the clue about Julius and Ethel I read it wrong. I was trying to think... did they have a famous executioner? What was his name? The only famous executioner I'm aware of is Christian Rath, but he had a pretty memorable name.
Otherwise, I really liked this quiz.
Not sure anyone outside a few dire hard quizers in the States will get Walter Winchell. I've certainly never heard of him. I think he would be far far to obscure.
OK, a better W? Lech Walesa. White House (the Soviet one) - "Russian parliament building that became the rallying point for Yeltsin and crowds of Muscovites during the failed coup to overthrow Gorbachev. "
So what if other countries boycotted the Moscow Olympics as well? The US was the most powerful/significant/first country to boycott it, and that's what really matters in this case.