Two queries about two "sentences"

1. When the chemist had shut his shop for the night he went through a door at the back of the hall that served both him and the flats above, and then up two flights and a half of stairs, carrying an offering of a little box of pills.(original).

I guess the original =
When the chemist had shut his shop for the night, he went through a door at the back of the hall, the hall served him and the hall served the flats above, and then he went up two flights and a half of stairs, he was carrying an offering of a little box of pills.
Question: Is my guess correct according to the original?

2. In our case until the time when, by divine intervention, the heat is turned off. (original)
Question: Is the original a complete sentence and grammatically correct?
if so, what is its meaning?

Question

Two queries about two  "sentences"

1.  When the chemist had shut his shop for the night he went through a door at the back of the hall that served both him and the flats above, and then up two flights and a half of stairs, carrying an offering of a little box of pills.(original).

I guess the original   =  
When the chemist had shut his shop for the night, he went through a door at the back of the hall, the hall served him and the  hall served the flats above, and then he went up two flights and a half of stairs, he was carrying an offering of a little box of pills.
Question: Is my guess correct according to the original?

2.  In our case until the time when, by divine intervention, the heat is turned off. (original)
Question:  Is the original a complete sentence and grammatically correct?
if so, what is its meaning?

Answer

Is this Dickens or something?   Long sentences with many clauses used to be quite popular.      2. Is not a complete sentence.     Probably it is paired with a previous sentence to make sense.

Answer

Your understanding of #1 is correct. We can discuss the second one through a lesson. :-)

Answer

I don't think there's a human being who could read that 'sentence' without asphyxiating. Unless there's an unknown reason for it, there's a clear problem with the punctuation.

Answer

With sentences this dense, one per question is enough! 😮‍💨 😉 
______________________________ SENTENCE 1

Yes, your understanding is correct.
______________________________ SENTENCE 2

“There is apparently such a thing as an ‘adjustment bureau’, founded, staffed and headquartered in Nigeria, which helps citizens, like the fabled frog, to consistently adjust to the rising temperature of boiling water. In our case until the time when, by divine intervention, the heat is turned off.”

—“Why Nigerians are no longer content with ‘suffering and smiling’ “
Tolu Ogunlesi (Special to CNN)

Ogunlesi is talking about the supposed Nigerian ability to withstand misfortune and maintain a positive outlook on the future. In this section he references the story of a frog placed in a pot of water, which is then put out over a fire. The water warms so slowly that the frog never realizes he is in danger until it is too late, when he is boiled for dinner.

Ogunlesi is saying the Nigerians are like the frog in the warming water. But, they have a government agency to help citizens deal with more and more adversity (hot water). Ogunlesi then says, sarcastically, that this agency will continue to keep Nigerians out of trouble, until magically (by divine intervention) “the heat is turned off”. That is, some outside force will take care of all of Nigeria’s problems. In other words, “Don’t worry about your misery, everything will be fine!

The sentence is grammatically incomplete, but is of a style that is often used, and reads well. There is more leeway in literature and “insightful, educated writing” such as this.

Answer

There is too much to unpack in your questions. I’d be happy to explain in a lesson.