Grasping and describing the exact meaning of words is an arduous task, and these pretty similar words probably differ in scores of subtle ways I can't even fathom, but here are a few notable differences between them I can see and put into words.
Crudely put, "手伝う" means "to help" (in the sense of "lending a hand") while "...
This is difficult partially due to the difficulty of differentiating dry up/wither/wilt/shrivel on my part, but here is a non-comprehensive answer.
枯れる means something completely dead. 枯れた花 is actually possible. The difference with 萎れた花 is that 萎れた花 may be just lacking some water. You can water it for the 萎れた花 to revive. I'm not sure how 'dried up' the ...
According to this, オ●●/●●ギ and ピ●● are probably おすぎ and ピーコ, respectively, who are twin brothers who have been nationally-known as being オカマ/おネエ since the 70's. I suppose ●●ン● is also a concrete name of someone, but I have no idea who it is.
～の役に立つ just means "to be useful for X", whereas ～の力になる literally means "to empower X". The latter should be used only when something/someone makes someone feel stronger, encouraged or more capable. Also, the latter does not always mean something/someone is useful in a practical sense.
For example, この枕は快適に眠る力になる sounds odd because good ...
かい is simply another version of the question particle か. You can read this post for details, but the main nuance is that you only use it when it's a yes and no question. You are correct for the meaning of てもらう and ため. The main subtlety here is that てもらう is used to request the ocean, not someone.
The literal translation would be something like: "In ...
The word "どことも知れぬ" means "No one knows where" or something like that. "どこででもある" is "can be anywhere".
If I were to translate this, I would translate it to "This is a country of everywhere and nowhere". Does that make sense to you?
Are they used by older people/in formal situations?
This depends on the word. Some are old enough and safe in business settings (e.g., メモる, トラブる, サボる). Some are rare and/or slangy. They are generally avoided in very formal legal documents, etc.
Are they really slang?
Generally yes, but many are widely used in day-to-day business settings, and there are ...
光る probably is the most neutral and can replace others in most cases.
ピカピカ光る implies the light is on and off alternately.
輝く sounds brighter light, but not necessarily physically. It indicates that the speaker positively values the light.
キラキラ輝く implies the changes in the intensity of the light, like ピカピカ光る. キラキラ光る is also possible.
光り輝く is used more in ...
To me, it looks like a new compound coined by the author. It's not uncommon at all for a novelist to make up a new kanji word (see this for another example).
It may be a rare term actually used somewhere in the past and known to experts. Still, an ordinary Japanese speaker don't know this word, and would not bother to look this up in a dictionary anyway. The ...
According to your explanation - since the boy speaking is raised by his mom only and doesn't know his dad, - it is very possible that he used the word to mean that his father is so rare that he hardly have a chance to see his father during his lifetime.
I think it's very likely that the word was used in such a way, as there is almost no chance to see a 天然記念物/...
よこす is limited to when the speaker is the recipient of the item: this makes the word almost always used in a command form e.g. よこせ, よこしなさい. This is also because this word is considered rude/casual compared to the others, making it common for verbal demands.
渡す is the regular and neutral word for "to hand over", often used with polite forms お渡しする/...
I googled the title. It wasドリンコはママの味
Fujiya (candy company)have a drink called drinkはママの味
It means it tastes like mommy made.
TV show made parody of Fujiya. ドリンコmeans someone's name or drink name maybe. But you need to watch the show.
If we can win this game, we'll win the championship.
With the prize money we won, we bought new equipment, had a victory party with our friends, and did many other fun things.
→There were many happy and good things.
Unnatural/non interchangeable usage:
うれしい人生. This is wrong usage of うれしい.
幸せな人生. This is good usage of 幸せ.