This thread is slowly turning into a nightmare..

That's because everyone is trying to engage in Socratic dialogues, and multi-threaded email lists don't lend themselves to that.

There is a sentence, which we are trying to translate; this sentence
is "he returns from the great hall at the Federation command centre on
Earth".

But the problem is, there is obviously some confusion with regards to
what actually its trying to say. Does it mean : "he returns (wherever
it is he is returning) from the great hall (which is) at the
Federation command centre on Earth", or "he returns from the great
hall (at Kronos) to the Federation command centre on Earth" ?

There is no to in the sentence to be analyzed. He returns from the great hall at the Federation command center on Earth means, in English, that there is a great hall, the great hall is at the Federation command center, and the center is on Earth. It cannot mean that you're going from a great hall on Kronos to a command center on Earth. At does not mean the same thing as to (or of).

If you want to talk about going from a great hall on Kronos to the command center on Earth, which is NOT what was asked for, then I'd say that as:

[Qo'noS] vaS'a'vo' tera' DIvI' ra'ghom qachDaq chegh

I added the Qo'noS to make it explicit that we're talking about a great hall on Kronos. Lemme add some punctuation to make it clear which phrases are independent here:

[Qo'noS] vaS'a'vo', tera' DIvI' ra'ghom qachDaq, chegh

There is no noun-noun relationship between the first two phrases. They are completely independent of each other. The only thing they have in common is that they both act as syntactic noun phrases to the main sentence, chegh.

What I'm trying to understand (and the more this thread continues, the
"trying" becomes "struggling"), is why -as De'vID wrote- "the pattern
is {X-vo' Y-Daq chegh} and not {Y-Daq X-vo' chegh}".

I don't know anything about there being a REASON it can only work that way. What I know is what Voragh has already pointed out: we have many canonical examples of X-vo' Y-Daq OVS and none of Y-Daq X-vo' OVS. The answer to your question is "that's just the way it is."

-- 
SuStel
http://trimboli.name