I appreciate all the feedback.
I consulted several people, including the fuel cleaning service that I hired, my mechanic, and the mechanic in the yard (Nelson Anderson, highly respected in the area) and all advised to not install a inspection port if not needed. I figure, the boat is 30+ years old, I have never had any issues with the fuel before, so why fix what ain't broke and the possibility of creating an issue...so no inspection port installed.
I am glad I had them "polish" the tank and mostly glad I had all fuel removed, the fuel was not in good condition. I watched them do it and was satisfied with what I observed. They came in two days prior and added a shock treatment to "release" slug/algae growth and then came back and used a high pressure pump to circulate the fuel for about 90 minutes at something like 20 gallons a minute IIRCC. Ultimately through a 1 micron filter. As they removed fuel they used a "wand" to spray down the sides of the tank essentially.
Cost was $425, call me crazy, call me proactive...I don't really know, but I feel better about it. One compliant with PetroScrub, the guys didn't attach the wires back to the sending unit, no big deal, took me all of 30 seconds.
With the new Racor Fuel Conditioning and using ValvTect BioGuard™ PLUS 6 I don't foresee any issues either
BTW, it was advised by several not to over use the Biocides, sometimes we think more is better, not the case so I am told