How long should each KSA be?
I would try to keep it to a couple of paragraphs or so. For example, you might talk about how your educational experience fulfills the KSA requirement in one paragraph, and how your work experience qualifies you in another paragraph.
What is the second KSA asking for (ability to establish and maintain public relation w/ diverse users)? I am really confused by this question.
In other words, can you deal with arrogant attorneys, clueless pro se applicants, and everyone in between.