Thank you, this is maybe a step in the right direction.
Addressing:
"topcap,expander plug or starnut and the bolt from topcap to expander/star nut that is required for preloading the bearings"
The topcap would be what you see when you look down at the top of the steer tube while riding correct? This is not part of the chain, it's similar to hose over a rope, protects the rope while not bearing stress if you take a fall.
I do not believe the expander/star nut is load bearing but I also don't know how it works, maybe you can explain.
ABTW?
HS? headset?
Top nut of the headset? I do think I am correct in saying that the steer tube and stem need to connect at some point, where exactly is this?
You are correct, I don't have much of a clue. I have seen a threaded headset, and used one if you mean riding, if you mean disassembling, no I have not used one.
I don't really want to be an expert, just semi-informed would be nice. Can you suggest a good schematic online to take a look at the inside workings of a headset?