I had an "outside the box" idea for maybe an improved public custom field type especially for KB. In CHD-1190 there is a request to add custom fields for individual KB articles, with our existing field types that opens up a lot of possibilities. It does not however allow for the two ideas here, votes and comments. To make those two work maybe we could develop a "cumulative" field type that combines multiple entries.

So for rating we could use a number field to tally the (1 through 10) rating customers gave you, to return an average.
And for comments, a multi-line text field to take customer feedback and combine them into a page of testimonials.