I just started a page in the Klingon.wiki listing metaphorically used
words and also metonyms. Okrand did not name them as such, and I noticed
ther are others that fit in such alist which were not explicitally label
as such, like {Soj} meaning "matter, affair" instead of "food".

Is that actually a metonym? I understand metonymy to be when you use an element of a thing to name the thing itself. For instance, when someone refers to "the crown" to mean the royal ruler. The crown is an element of the royal person being used to name to the royal person.

Soj food is not an element of a matter or affair that can be used to name a matter or affair, so it's not a metonym.

3. Some idioms consist of only a noun phrase, like {naH jajmey}.
Wouldn't that also be a metonymy?

That's not a metonym either.

-- 
SuStel
http://trimboli.name