Is there a word that means to do too much or does too much?

a littleI do not think that there is a single word in English that means, specifically, not too much. "Adequate", "satisfactory", "sufficient" and "enough" mean… enough. "Inadequate",...

The Italian word "troppo", usually used in the phrase "non troppo", not too much. Allegro non troppo, for example.

nag :)

overload

If someone is "too much" it usually means that the person using the phrase finds them too be a bit out of the ordinary, and a character in a generally entertaining yet unusual way.