To play my own trivia game:
1) Who was the last person who served as S of STate to run for President?
Haig. Ran briefly in 1988.
2) Who was the last person who served as S of State to be a nominee of a party for President?
I think this was James G. Blaine, at the end of the 19th century. William Jennings Bryan was nominated again and again by the D's, and eventually served briefly as S of State under Wilson, but that was long after he had been the nominee. (Did Edmund Muskie serve as S of STate? Didn't he run for Pres at some point perhaps in 1976? I'm not sure).
3) Who was the last person who served as S of State serve as President? James Buchanan.
I "think" those are right, though I would welcome any corrections.
I remember now that Charles Evan Hughes was the Republican nominee at one point. But I don't remember if that was before or after he served as S of State.