Because the sentence begins with the clause Al kom die verhuiswa laat. That whole opening clause takes the first position in the sentence.
In Afrikaans main clauses, the finite verb usually comes in second position. So after that opening clause, the next element must be the verb:
If you remove the opening clause, you get the ordinary order:
This is the separable verb uitpak, meaning to unpack.
In a main clause, separable verbs split:
So:
You will often see this with other verbs too:
Verhuiswa is a compound noun:
Afrikaans usually writes compounds as one word, so verhuiswa is normal. This is very common in Afrikaans:
So if you see a long noun, it is often just smaller words joined together.
In this sentence, ons means we.
That is because it comes right after the finite verb pak, which is where the subject appears in this word order:
If you wanted our, ons would have to come directly before the noun it belongs to:
So:
Because Afrikaans can use a bare plural noun when the meaning is general or indefinite.
So:
Both are possible, but they mean slightly different things. Without die, the phrase is less specific.
Yes, very often you can.
With alhoewel, the word order changes:
So:
The meaning is very similar, though alhoewel can sound a bit more explicit or formal.
The comma separates the opening concessive clause from the main clause:
This is standard punctuation in Afrikaans when a clause like this comes first. It helps show where the first idea ends and the main statement begins.