I have some questions concerning Homonym and certain words in particular.

(A) My understanding of Homonyms is that they are words with the same pronunciation and spelling, but with different meanings. This means that one word (e.g. bark) can carry several different meanings (e.g. for bark, it can be “a noun as in the cry of a dog”; or “a verb as in to refer to the action of stripping the bark from a tree”; or “a noun referring to the tough protective outer sheath of a tree trunk (i.e. the bark)”. In other words, a word that is considered to be a homonym, may play different roles (i.e. the same word may function as an adjective, noun, verb, adverb etc) and that even within each role, this homonym may carry multiple meanings (e.g. the word “destroy” functions only as a verb, but even so, it carries several meanings, each of which is unique and different from the rest, such as “to end the existence of (something) by damaging or attacking it”; “to ruin (someone) emotionally or spiritually”; “to defeat (someone) utterly”; and “to kill (a sick, savage, or unwanted animal) by humane means”). Is my understanding correct thus far?

(B) I realized that dictionaries generally list down the meanings (aka senses) of a word via a particular order, usually with the most important or commonly sought after meaning listed first followed by the other senses. In addition, for each sense, there are usually sub-senses attached to it. To quote an example, in one dictionary, the verb “destroy” carries the main meaning (sense) of “to end the existence of something by damaging or attacking it”. This is then followed by several sub-senses such as “To ruin someone emotionally or spiritually”; “to defeat someone”; “to kill an animal”. My questions then are on such sub-senses and how/why they are not considered to be a main sense.
(B1) Firstly, concerning the word “destroy”, am I right to say that the main sense as well as the sub-senses which I’ve listed above is correct and that each sub-sense is unique and different from the rest, and thus each sense (aka meaning) deserves its own mention in the dictionary (i.e. there are no overlaps in meanings)?
(B2) Secondly, am I right to say that generally speaking, each sub-sense represents a unique meaning which is different from all other main senses and sub-senses (i.e. again to mean no overlap in meanings)?
(B3) Thirdly, why or how do such dictionaries determine if a particular sense of a word should be a sub-sense or a main sense, since each sub-sense is a unique meaning that deserves its own, separate explanation?

(C) Lastly, another word that I’ve noticed people use differently is the adjective “fair”. Many dictionaries contain multiple meanings of this word, but the most common are to mean “beautiful”; or to mean “(of a person) having a light complexion or hair” as well as to mean “treating people equally without favoritism or discrimination”. However, for myself, I’ve always like to use ‘fair” to mean that something, for instance a statement or description, is accurate, valid and correct. Am I wrong to use “fair” to mean “accurate/valid/correct”?

Sry for the lengthy post and looking forward to your advice on (A), (B1, B2 and B3) and (C). Thanks again!

Regards,
Shizuka