Don't be shy about posting a link to your proposal, doing now for you: Steem Proposal - Account Rating System

From your proposal:

To put it another way, no belief or opinion is more valid than another. Therefore, such a system could not include stake as a variable.

I don't agree, stake related vote is a meassure that turns a sybil attack into a costly endeavour.

Also experience makes certain opinions more qualified than other ones.

It's not logic to put the same value on a witness with 0 year experience at the same level of a witness with 4 year experience. When you are looking for a job, that's an important item.