Overall it does seem like these are good changes, however I understand why some of the admins disagree with the changes, especially due to changes made to their own individual projects. I do think that the rating part looks cleaner as part of the infobox though.
The multiple promos in infoboxes is something I always wanted to do, but mostly to show the different actors who have played the character. I do think adding a different promo for every year is excessive, but most characters only get new promos every few years so it shouldn't be much of an issue. I also think this would be a good change because each tab adds extra context to show which year the photo was taken, which would explain why characters might look different in the show now due to being older or just having a different hairstyle like Denise, who had her last on-set promo released in 8 years ago and looks quite different now.
As for the research section, it does make more sense to have the list of appearances and gallery sections there but there will still be a 'See also' section of the page for characters such as Phil Mitchell who has lots of other pages listed in this section. Would these pages (such as Who Shot Phil?) also be listed in the research section of the infobox?
