@thielrules,
What an impressive undertaking and write-up! I must confess that I lack the knowledge required to judge the success of many of your choices in making mods on the original 3.5 design. My negative experience with equalizers in the past makes me hesitant to depend on EQ to fix problems in replacement drivers or make decisions on a "house sound," but I have absolutely no experience with modern digital EQ so I am not in any position to offer an informed critique.
Above all, I will be very interested in what the speakers now sound like. Please let us know your listening impressions as you log some serious listening time with your "renewed" speakers. Thanks for sharing all this great information!