It's hard to argue that Switzerland is "led" by a chancellor. The highest level of the Swiss executive branch is a seven-member council, one of whom is determined as a largely ceremonial president. The Chancellery of Switzerland is the staff organization of the executive branch, headed by the federal chancellor. In analogy to the U.S., the chancellor is the president's chief-of-staff, though elected to this position, not appointed.
As a Brit I feel incredibly stupid for not realising the 1707 question, I knew I had heard of it before but immediately started trying things like Castile and Aragon whilst ignoring the obvious.
The "Intelligence" part of the MI6 answer doesn't show up until the answers are there. Therefore, I'd argue that MI6 could just as easily stand for Mission Impossible: 6.
I agree with this. I did try "Mission" here as well thinking it referenced the movie. Although to be fair, the Mission Impossible movies show it as "M:I" and not "MI". Maybe the clue could include a bit more detail?