I have a question about negative sentences with "much" in English.
I don't much like it. I like it not much. - as I understand it means "I like it, but not very much".
I don't like it. - it may be possible that I neither like nor dislike it.
I don't like it much. - does this mean that the person likes the thing but not much or the person dislikes the thing? What do we negate here "liking something" or "liking something much"?
I don't like chocolate ice cream much.
I don't like Vince Vaughn movies much.
I don't like hiking much.
I don't like hospitals much.
In all four of these cases, I would take it to mean that the person doesn't particularly care for the named item or activity. This could be anything from a moderate or mild dislike to a more moderate disinterest. In other words, perhaps this person has a genuine dislike for chocolate ice cream, but more likely they simply prefer other flavors over chocolate. Perhaps this person avoids hiking entirely, but maybe the person wouldn't mind going on a short hike a couple times a year. I wouldn't want to make too many judgments bases on such a vague statement, but I will say this: I wouldn't expect this person to be hitting the hiking trails every other weekend and ordering chocolate ice cream at that quaint little store near the end of the trail every time. But if the choice was between chocolate ice cream or no ice cream, it's difficult to know which way that might go based on the one statement alone.
It's hard to say whether the "much" modifies the thing or the degree of (dis)like because the expression is somewhat idiomatic and flexible in its application.
As others have said, one of the expressions in your first line ("I like it not much") is not really idiomatic and wouldn't be said by most native speakers.
"I like it not much" into Google, and got only two hits. One of them shouldn't count, because it's actually two consecutive sentences: one sentence ending with "...I like it", followed by another that begins with "Not much...". The other hit was this page. That should tell you everything you need to know about this non-standard wording.
I don't like it.
This means what it says. You do not like it. It usually equals I dislike it.
It is rarely possible that the speaker means something else. E.g. "I don't like it. I LOVE it." But this will be immediately qualified by the speaker as part of a dramatic effect (or should be) and isn't a default assumption with the phrase.
For example:
A: I don't like those oranges.
[B throws away the oranges]
A: Why did you throw away the oranges.
B: You said you didn't like them.
A: I don't like them. I love them. Take them out of the trash.
A is being a real smartass here and no one would blame B for being mad at A.
I don't like it very much.
Very much here is fuzzily expressing the amount of "I don't like", and very much means something like 80%-90% - not 100% but more than "half."
