Hi fsa,
No Boyler, I cannot see this. In Guopu's Zangshu, even a copper bell has qi and the chest nuts far away responded to it.
Could you explain what does above statement has to do with
qi=magnetism? Copper does not have magnetic qualities (which is,
BTW, one of numerous proofs that
qi could not possibly be identified with magnetism). Even if it has (which, of course, has not), it's man-made thing, and according to prof. Cheng, whom you brought up as an authority,
we should take the magnetic deviations, that is the magna under the earth affecting the needle, into consideration, but not the electromagnetic influences generated by man-made things
I suppose I don't have to mention that "chest nuts" also do not have any magnetic quality, or I do?

By now, the thread becomes little bit ridiculous and senseless, and I am little bit tired of pointing out the obvious, as every schoolboy knows such things.
The magnetic field of the earth moves a needle
This I must agree, and it was never a subject of debate

and pointed it to a constant direction,
This on the other hand is not correct. Earth magnetic poles are in constant movement, besides there are local magnetic fields and magnetic fields caused by man-made things, which render magnetic needle of a compass and therefore
luopan too inaccurate. That is it also indicated deviations, declinations, and/or inclinations. In short,
it's not pointed to a constant direction.
the soldiers used it to win battles, the sailers who lost at sea are saved by it and the Feng Shui experts use it to find Sheng Qi, so Master Qin's comment "地磁即是氣 (geomagnetism is same as qi)" do made sense to me.
I've used examples of soldiers, sailors, etc. to point out that each of them who is professionally using a compass of some kind, should made corrections for magnetic declination in order not to get lost, to arrive at right destination, or to determine true direction of some object - that is they are, although using compass, in fact looking for the true or geographic directions.
The same thing should do
fengshui experts too, according to some
fengshui classics, say, (surprise!!!),
Book of Burials 
Feng Shui deals with qi and this qi is not just one single thing,
Fengshui deals with
qi and this
qi is just one single thing, which could transform, sometimes visible, sometimes invisible. One can even hold it in the hand

Ooooh, such a mysterious that one single thing is

it is a synergy of Heaven, Earth and Human coming together to make Sheng Qi, qi that encourages growth and nourishes us ("To bury is to take advantage of the Sheng Qi" - first line in the Zangshu).
What is the connection of burying with
qi as magnetism?
In this sense, everything has qi
Not everything has
qi.
and we cannot just separate magnetism/ci 磁 with qi 气/氣/炁.
Yes we can

It seems you have taken a very narrow definition of qi out of a dictionary and I have taken a much broader one out of the classic. Here lies our difference in approach to Feng Shui.
I have no definition of
qi that is my own, and its not narrow nor only from a dictionary

On the other hand, excuse me if I missed it, but I did not see any definition you brought up from classics - statements from some professors and masters yes, but prof or definition no - which connects
qi with any form of magnetism as yet.
To summarize what might look like one (but unfortunately isn't):
copper bell has qi
chest nuts far away responded to it
To bury is to take advantage of the Sheng Qi
This is all in this thread so far what could be considered as your quotations from classics - in this case from only one (unofficial but real) classic, and I can't see any reference to magnetism there, on the contrary as I have said above.
copper bell has
qi - copper has no magnetic qualities
chest nuts far away responded to it - chest nuts have no magnetic qualities
To bury is to take advantage of the Sheng Qi - (referring to a corpses, or more specifically to bones - which) have no magnetic qualities
Now, from the above you say it is clear to you that we cannot just separate magnetism/ci 磁 with qi 气/氣/炁.
On the other hand I say that in above quotations I do not see any mention of
qi which could be connected with magnetism whatsoever. Is there something, anything I missed out? What is it? Anyone?
With all my effort of imagination I must admit I can't understand your reasoning, but it must be only me

I think the most reasonable explanation is that aliens hijacked my friend, who had a beautiful critical and analytical mind of an architect and scientist, who even promoted
fengshui as a science, and turned him into one of newagers who see things where they are not. Or it was me who was hijacked?

BTW, I would still like to see quotations from classics which support Master Qin's argument. Maybe they will open my eyes.