Hi Aishokuareno
I think you've pointed out some clear inconsistencies or logic flaws, & I hope 1 of our wonderful J-Mods wanders by to clear things up.
I imagine the answer revolves around the incompatibility of citadel code to the main game.
Essentially you have to access it to find out anything.
Regarding visitors/build tick/dilapidation, here's my understanding, though I haven't researched citadel matters for a long time.
From memory:
the citadel will degrade 1 tier every 2 weeks.
The new build tick begins once the 1st member visits after the previous has finished, but if you don't visit in a week, it alternates btw dilapidating & degrading citadel tiers.
I would have thought the new WEEK begins when the 1st member visits, but based on the information you have provided it doesn't sound like it works like that.
You have taken the time to lay out your questions very clearly, & I hope that one of our wonderful J-Mods finds the time to clear up the questions that haven't been answered, even if they aren't the answers you want.
GOOD LUCK!