The smoke/steam effect on the drop hole has been removed, the whole spray system/pipes are gone. Sad days...
The mist effect you talk about is not on currently - I personally believe the reason for this is because The Smiler will tap into the same water source as Oblivions misters and will be used for either The Giggler, The Inoculator or both.
Submission still rattles like crazy so no referb there and enterprise is still the same.
Submission and Enterprise have both had extensive refurbishments - Enterprise more so with having a completely new central hub and arms. Submission has had both arms checked over and put back together and both arms are working but only one is currently used due to there not being a need for the other just yet. Once The Smiler opens chances are there will be a need for both arms to be used.
Not sure what you mean when you say it 'rattles' but if you mean you can hear noises like stones rolling around inside it is fragments of metal inside the main carriage base that are there when it was fabricated.
Its just a case now of the smiler opening, I expect they will shut down the x-sector before removing the banners/fence and while testing.
They won't need to shut down X-Sector as the boards being removed will be the last thing coming down the day before the ride is due to open and all the boards can be removed the night before once the park has shut for the day. I also doubt they will shut X-Sector due to testing as there is a safe working environment/envelope around the ride already. I guess effects testing may happen once the park closes at night to keep them a surprise - even though everyone has a good idea of what will happen effects-wise.