At what I should come tomorrow.
I don't know how you arrived at this sentence, but it is wrong.
You could just say "I should come tomorrow." but as you are looking for a time you wouldn't get much of a response because it is not a question.
"Should I come tomorrow?" gets you a step closer and gives you an answer either "yes" or "no".
Now, "At what" is a verb phrase, and it needs a direct object. In your first sentence, you are missing the direct object. In your second construction the word "time" is your direct object.
Essentially you want to ask yourself "At what, what?" meaning, what am I looking for? In this case (since it's a question) What so I want someone to respond with? Do I want them to respond with a place, a time, or something else? Because you want them to respond with a time you need to indicate that you are looking for a time as an answer.
In your first construction there is no indication that you want a time. "At what what?" - there is nothing. "I should come tomorrow" (I believe) is a prepositional phrase, which modifies "At what". Since there is no other words in the sentence "At what" is left hanging and you don't know what is being asked for. So you need the word "time" there so that you have a complete sentence.
So your correct answer is:
At what time should I come tomorrow?
However most people would say:
What time should I come tomorrow?
Yes, "belong" can indicate ownership. Or perhaps I should say the opposite of ownership: "I own this box" implies "This box belongs to me."
Whether you use "belong" or "belongs" simply depends on whether the subject is singular or plural. "It belongs" but "They belong".
You can use it in the simple present or in other tenses. "This belongs to Bob." "This will belong to Bob" (perhaps after he has proven himself worthy). "This belonged to Bob" (but it doesn't belong to him any more). Etc.
You don't say "is belongs", just "belongs".
Best Answer
It seems fine to me is the only sentence which makes sense.
The word fine is an adjective and must be attached to a verb. "It seems to be fine" is correct, "it looks good to me fine" is incorrect (I've replaced "seems" with "looks good" to highlight why this sentence is wrong).
This is also wrong, even though the sentence uses the verb to occur!
Things can't "occur good", in the same way things can't "love good" or "run good". It could occur suddenly to you, because suddenly is an adverb and not an adjective.
Why is to occur different than to seem? Only verbs which describe a state of being can be paired with an adjective. An object can smell good, taste good, look good, and be good. Verbs which describe an activity cannot be paired with an adjective; an object cannot sing good, laugh good, break good, or go good.
For the same reason as above, it can occur to you suddenly, but it can't occur to you good.