In general, ～ようにする is simply about making/keeping something in(to) some state/situation described by the preceding verb. ～ことにする is about making a decision/rule/resolution.
見えるようにする to make it visible
見えるようになる to turn/become visible
見えることにする to decide to make it visible
見えることになる a decision is made to make it visible
Now let's look at each example:
Basically 幸せ means happiness. But I have seen this conversation in an American movie:
Mother: Is she your girlfriend? Looking disappointed
Son: No, are you happy?
This "happy" is 嬉しい in Japanese. So it depends on the context.
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.
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/...
I think "体が動かない" can mean both My body won't move and I can't move my body. I believe it's just matter of situation.
I can't move my body would fit better with "体が動かせない" though.
Edit: Forgot to mention that "体が動けない" doesn't sound natural to me.
If you meant to use it as "My body won't move", it's fine with "体が動かない&...
間違い (noun); 間違った (adjectival); 間違う (verb)
誤り (noun); 誤った (adjectival); 誤る (verb)
偽【ぎ】 (noun; used only in the context of logic or programming)
誤る is more formal than 間違う. "That statement is false/incorrect" can be:
For one, 加える is more formal than 足す。 足す can also mean to add, as in adding numbers / mathematics. The really small difference is that 足す is generally used when adding to an already existing quantity, while 加える is more used when adding something new.
Both mean to add sugar to coffee, but the former would be used in a ...
I think you are either reading too much into the apparent similarity between “kind” and 種類 or missing the peculiarity of the English word “kind”. The usage of “kind” in “a kind of X” is kind of exceptional. In fact, from the way you phrased your previous question, you seem to perceive X as the core part of it, rather than “a kind”. This clearly contradicts ...
Since you have read the link you provided I assume you are comfortable with adding 方 to the masu-stem of a verb to mean 'way of doing verb' e.g. 食べ方 (way of eating). The question is, what happens when you have a する verb? You might think something like 勉強しかた would be correct but, just like other uses of する, this one is irregular. The correct way to write it ...