I'm not a native Korean speaker and I'm not very proficient, but I think 하다 is added when they aren't modifying a noun or they aren't a noun. Like 생각 --> 생각하다. If you said, "I gave up the thought of loving you" then you would have 생각 as a noun. Love being the verb. If you said, "I didn't think you were here" 생각하다 would be used. Since you're doing the thinking. Basically it's (noun) + 하다 when: It's not noun or adjective. But is the action of the subject. Use just the noun when: You're using the noun form of the word. 생각 (thought), 생각하다 (to think). Or when you're using it as an adjective 무섭다 --> 무서운 I hope you understand! If you have questions feel free to ask me!

좋다, 싫다 versus 좋아하다, 싫어하다. You say "to differentiate between an overall like or dislike as opposed to the dis/like of an object", but this might be a misunderstanding. The importantl difference is not so much about whether it is overall or specific("object"). It has more to do with their usage being specialized to the first person. 좋다, 싫다, etc, when used as the main verb of the sentence (i.e, not in a sub-clause) and in the sense of liking/disliking someone, are only usable for the first person "I". When you say it for the second or third person, you must use 좋아하다 or 싫어하다. Examples: - 나는 개가 좋아: I like dogs. It has the same meaning as 나는 개를 좋아해. - 너는 개가 좋아 / 그는 개가 좋아: BAD. Should be 너[그]는 개를 좋아해. The exact cases where this first-person restriction applies is not that clear cut, but we can say it is in "simple and direct" expressions. That is, the verb is the main one and has the normal statement-like ending form 좋다/좋습니다/좋아/좋아요. If an indirectness is introduced so that the verb form significantly changes, it can be used for a non-first-person case too. For example "내 친구는 그 여자가 좋대 [좋다고 해]" is fine because it is in a quoted clause. 내 친구는 그 여자가 좋은가 봐 is also okay as 좋은가 봐 makes it indirect and uses a different verb form. The other important thing to know is the class of verbs for which this rule applies. They are what might be called "emotion" verbs. They include 좋다, 싫다, 밉다, 기쁘다, 슬프다, 화나다, 고맙다, 감사하다, 아쉽다, 부끄럽다, 무섭다, 창피하다, 당황스럽다, 미안하다, 놀랍다, 행복하다, 답답하다, and so on. So for the above group of verbs (adjectives technically), you can use the ~하다 version when speaking of someone else, as in 그는 슬퍼하고 있다, 너는 걔를 미워해, 내 친구는 실패를 아쉬워해, etc. I hope I answered your question. If not, please ask again with the specifics.

If you were asking about 좋다 vs 좋아하다 as used for the first person, here's some more details. - 좋다/싫다: refers to direct, natural reaction, usually at a given time. - 좋아하다/싫어하다: indicate a person's general preferences. So if the object is a person (나는 그 사람이 좋아 and 나는 그 사람을 좋아해), they have nearly the same meaning. When the object is not a person, their meaning may be somewhat different. You also mentioned 밉다/미워하다 and 그립다/그리워하다 saying "when this change is allowed". Again, 밉다 and 그립다 (adjectives) cannot be used directly in the second or third person. Both adjectives (밉다, 그립다) and the ~하다 verbs(미워하다, 그리워하다) can be used for the first person, but 밉다 and 그립다 are definitely better choices. In some cases, like 나는 그 사람을 미워해 and 나는 그를 그리워해, the ~하다 verb may work, but in others (나는 슬퍼해, 나는 부끄러워해) they sound strange. So the simple answer would be: except for the special case of 좋아하다, 싫어하다, use the adjectives for the first person (나는 기쁘다), and the ~하다 verb for the second and third person (그 아이는 합격을 기뻐한다).