5 vowels in a row
There is only one common word in English that has five vowels in a row: "queueing".
6 consonants in a row
The word "knightsbridge" has six consonants in a row, as does "latchstring".
5 vowels in alphabetical order
There are several words that feature all five vowels in alphabetical order, including "facetious" and "abstemious".