1. 후렴구: 후렴 + 구(phrase). Thus, expression-oriented one. 싸비 or 사비 originated from Japanese, and it's mostly only for music-related workers such as song writers.
2. 동률 means "same ratio" and 동점 means "same scores."
3. 각인하다 and 새기다 can have the same meaning, but the latter one is used for wider meanings as it is a native Korean word. Usually, Sino-Korean words have narrower and stricter meanings.
4. 탕 is a formal word for 국, but today, 탕 is mostly fossilized so that it refers to particular soups such as 설렁탕. Simply just remember 탕 is those with -탕 at the end. 찌개 is thicker than 국.
5. 혹여나 is used for "in case," and 혹시 also means "by any chance." It means 혹시 has more meanings.
6. 고대하다=학수고대하다. But we prefer just simply to use 기다리다.
7. 존중: respect; acknowledging something or someone's existence or value. 존경 contains that you "admire" someone that you deeply respect him or her and want to accept his or her values.
8. 그간 is used mostly about the period between presence and a certain point in the past. 그동안 means "while doing so." Thus, the latter one has a broader meaning.
9. 힘 들어가다: you get to use your muscles; sometimes also when you get to use your brain power. 힘들다 means "to be (physically) tiring/tired" which can be "to be exhausted/ing."
10. 최근 들어서 is used when we mention or explain a certain event that recently happened. 최근에 is similar, but it can be used in questions like "최근에 무슨 영화 봤어요." 최근 들어서 is actually available, but not common in reality.
11. 어디나 and 어디에나 can be almost the same considering that 어디 can function as an adverb without 에 in many cases. However, 어디 also can be used as a pronoun, like "어디를 좋아하세요." So, when 어디 is used as a subject or object, then it should be 어디나 if we attach (이)나.
12. 어떻게 "how" and 뭐를 "what." I don't think this would be that different from English.
13. 오늘 하루 "one day today." So, it's an emphasis of 오늘. It sounds like we need to talk only about a single day in presence.
14. -류 means "sort," "kind." Thus, "fish sorts." 생선 makes us not think various kinds of fish, but 생선류 does. To me, 생선류 has me vaguely come up with a number of kinds of edible fish like lining up images in my head.
15. 요즘따라 is typically used when we say recent tendency that is by and large different from how it used to be. 요즘 simply means "these days." So, 요즘따라 is more like "for some reasons/strangely, these days ..."
16. 뻥카치다 and 뻥치다 all mean the same. The two are slang words that mean "to tell a lie." Unless it is zero-formal situations like YouTube, 거짓말하다 is recommended.
17. 담이 걸리다 describes that you have a shoulder ache as your muscles there are exhausted. 쥐 나다 means that you have a muscle cramp.
18. 어찌 됐든 and 어쨌든 these two are interchangeable as long as they mean "anyway," I think. However, 어찌 됐든 is a phrase. It means when we mean "no matter how it became/is now," the former one should be used.
19. 겁나 and 겁나게 are the same. Approach them like 뻥카치다 and 뻥치다. It means the two are also only for zero-formality situations.

• 동률/동점: 동률 is when ratios are tied, like votes coming out 50:50, and 동점 is when points are tied
• 고대하다/학수고대하다: in Korean you say you stick out your neck (to look out for something to arrive), and 학 means crane (big bird with long neck) and 수 here means neck, so you’re eagerly waiting for news with a neck like a crane — it’s just an expression meaning you’re really anxious for something to arrive
• 존중/존경: 존중 is like respecting the rules or respecting what someone does/says, 존경 is like respecting a person and looking up to the person themselves
• 뻥카치다/뻥치다: 뻥카 is like bluffing like you have a good hand of cards when in fact you don’t; 뻥치다 just describes any lie
• 담이 걸리다/쥐 나다: 담이 걸리다/결리다 describe stuff like waking up unable to turn your neck; 쥐 나다 is just cramps from muscle spasms

Lists getting too long so I will just explain a few things

1. 후렴구 후렴 싸비 all mean the chorus and there is no difference in meaning but people who major in pop music or are into vocal technique often say 싸비 but honestly when I was younger everyone just said 후렴. These days people around me and I usually say 코러스 which comes from English I see 싸비 a lot online but not so much in real life.

2. 혹시 is something you hear a lot in everyday conversation (혹시 그거 아세요?)

혹여나 is used mostly in written language like essays or poetry (혹여나 그렇게 생각하신다면..)

1. 그동안 is a basic expression that works in both written and spoken language (그동안 진짜 고생 많았어)

그간 is mostly used in letters or reflective writing like memoirs or recollections (그간 잘 지내셨어요? Or 그간 많은 일이 있었다)

1. 요즘 just means these days and is neutral (요즘 두바이 초콜릿이 유행이래)

요즘따라 means it was not like this before but for some reason it has been like this lately (요즘따라 안하던 소리를 다 하네)

Have you tried a combination of Naver Dictionary (blue Korean-English one) and a Naver image search? I only skimmed your list, but that would clear up at least a few like number 4. There's going to be a little overlap with types of soup, but the dictionary definitions (you have to actually click on the word to read the full definition) and pictures will make it very clear. 3 stars means it's a very common word, 0 means less common, and always check the example sentences for nuance.