I don't know if it is appreciated by others but your issues seem to be different than issues that others have had. For example, on one of my bookings, MSC somehow changed my GENDER. Everything else (name, DOB, etc.) was correct but I was listed as a female. It is impossible (for me) to change that one once everything is booked and it took several months for MSC to correct it. I don't know how common it is but I have never seen anyone else on the forum have that issue just as I haven't seen anyone else have your issues....and nobody else has had the issues that "mscdivina2016" has had. 😉
As for middle names, we've never had a problem. On my last cruise, we walked into our stateroom for the first time and found a plate of cookies. What made these cookies unique was that my kids' first and middle names were written in chocolate sauce on the plate. The parents had champagne flutes to go with the extra bottle that was actual champagne instead of the standard sparkling wine bottle that was on the table. My point is that your "middle name issue" with MSC is the complete opposite of my middle name experience. The log-in and check-in issues that you have had to go through are relatable since they are nearly as frustrating my "gender issue" so you can count me in as someone who understands. As is the case with many MSC guests, my experiences on the ships are 1000x better than what happens with the website.