In an email thread, Erik mentioned that
There is the ability now though to join TestSearchSatisfaction2 against CirrusSearchRequestSet, although we've never done it. The id field in CirrusSearchRequestSet should match the searchToken field in TestSearchSatisfaction2.
Which, if this is possible now, opens the door for us to, say, deconstruct queries into features in Hive via DeconstructSearchQueryUDF and then combine that with clicks data from TestSearchSatisfaction2.
Now, this task isn't to answer a question like "do queries that use regex have a higher clickthrough rate than queries that don't", but just to see if this is something we can actually do if a future analysis requires us to do this.