Thanks!
I put in my design document an ironclad rule that I would not touch the party members after the player has acquired them. The playable party is (almost) completely independent from the story. I'd be MAYBE willing to break this rule if a character canonically dies or if there was be a branching story path where you completely abandon the Agency or something. I understand the immersion aspect, but I draw this design aspect from more modern games like Star Rail. Players have their favorite characters and team comps, and while RPG Maker allows adding and removing party members at any point, I feel it would be detrimental to the overall gaming experience. Many would find it annoying that you can't suddenly use the character you've put most effort in and given the best gear to just because this bit of the story happens to dictate so.
The latter feature is likely possible, but would require a lot of modding. Especially if it needs to show the current equipment, since I'd need to have graphics for every single armor/weapon/shield I put into the game. Not impossible, but too much work for one guy considering it's a purely visual feature. Canonically most of the characters wear the Agency uniform anyway.