How do I search the forums so that I can review similar questions before posting a question/comment?
When I consider the OP's requirement "review similar questions before posting a question/comment" I'm not convinced that any other search system is likely to be better than Google.Unless the request to the search engine uses words that are contained in a Thread that Thread won't be found. For all its qualities, and the huge ongoing investment in it, Google is still really primitive compare to the human mind.
I don't have confidence that the Arduino developers could do a better job - particularly as they don't use the Forum regularly and cannot be aware of their customers' experience.
I don't think "WProgram.h" is a good example because it has a very specific solution and it really does not matter what Thread is identified.
Unless the request to the search engine uses words that are contained in a Thread that Thread won't be found.
Having a Forum search facility that can produce a list of 500 Threads with "MAX6675.h" without any order of priority is not necessarily much value.
after which that thread would be the reference for everyone else with the same question (like how Stack Exchange is supposed to work).
I really like the concept of Stack Exchange.