Incompetence should carry liability as well. If some politician signs his name to random documents without understanding what he's doing and causes harm to people, he should simply pay the price to make the other party whole, whatever damage was caused should be undone to the fullest possible extent and he should be removed from office for good measure because he's clearly too dumb to exercise it responsibly.

That's the benign case. If it turns out he wasn't actually incompetent but was signing things in exchange for money or favors he should go to literal death row. Proven corruption should result in the death penalty for all involved.