What is the difference between "weighted" and "weighed"?

Solution 1:

It would be better to use weighed down here. Weighted down is usually found in a more literal context of adding ballast, as in, "The balloon was weighted down so it wouldn't fly away". Weighed down is appropriate for a more figurative context of adding something unnecessary or undesirable.

Solution 2:

"Weighted down" is redundant.

Weighed down and weighted (no preposition) can mean the same thing in some contexts.

Weighed down can, in principle, denote some kind of burden - good or bad.

Weighted, on the other hand, is a purely technical term: an adverbish adjective meaning "with added weight," "with some ballast."

For instance, the keys on professional electronic pianos are typically weighted. They bounce back slower than ordinary plastic keys in order to imitate the "real" piano key action. There are fully-weighted and semi-weighted versions.