I am using my own Italian-Chinese-Chinese-Italian dictionary to help you, I hope the following answer can help you.

Sober, clear: Lucido (accent on Lu), or Lucidaménte (accent on Men)

Spunky, dashing, uninhibited: Disinvolto (I haven't touched the word myself, but the accent should be on Vo), or Libero (accent on Li). But to interpret the word sprightly, Disinvolto is more accurate.

Rationality, sanity: Razionalità (accent on the last letter), Razionalismo (accent on Li) is rationalism.