To shun something is to take pains to avoid it. To eschew something is to abstain from it or keep away from it. They are very close in meaning, but eschew is more often used to talk about the avoidance of a course of action that is perceived as unwise or detrimental to a specific outcome. The verb shun is more likely to be used to convey aversion or loathing.
The informal noun druthers means “one’s own way, choice, or preference,” and it is overwhelmingly used in the conditional, like this: “If I had my druthers, I’d read Synonym of the Day all day long! But alas, I must get back to work.” Fun fact: druthers is the plural of druther, which is an alteration of the phrase would rather.
Obscure is used to describe things not widely known or understood, such as an obscure literary reference (a reference that does not land well because nobody gets it). Arcane is used to describe things that are known by very few, perhaps intentionally, such as secret or guarded knowledge. You might hear arcane used to describe knowledge of the metaphysical or occult, or to describe rules or information that is so highly technical, most people don’t bother to learn it.