John, First off, I have been looking at the profile scores for a few months and think they are a great addition, well done.
In the effort for constant and never ending improvements, here are some suggestions to consider.
Think about adding a time limit on pulling your data for calculations, that is historical for when someone joins the Exchange. Pulling all historical data on response time, ratings etc will skew the numbers to a historical plain, not telling the purchaser what the selling is currently doing.
Case in point, Randy from Mar 16 post is penalized because he did not send back a message to the buyer for thanking him. How many years will this be pulling down his score. He would be better off starting over with a new name. In my opinion, this metric should be started with the metric rating rollout and only look back 1 year. This would let the buyer know what the seller is currently doing.
Same with ratings. With an ag product, crops are different each year. Heat domes and wildfires made a difference last year. Many European hops are not irrigated, so they have even bigger fluctuations in quality. I have one bad rating from a buyer that did not tell me he got the wrong crop year. Zero communication till he sent in a rating. No chance to fix the issue, by replacing, refunding etc. A great addition would be to require all low rankings to contact the seller first, then make a rating.