I personally don't see any significant differences in meaning among all examples you've given, other than the fact that different words are used.
If we compare for example:
- dollars of imports
- dollars in imports
- dollars worth of imports
We get these results from Google NGram Viewer.
We can see they are all used, with none of the three being extremely more frequent than any other.
These results aren't intended in any way to argue my opinion that they mean largely the same thing in your example sentences; I've just given it for your own reference.
You can also see the results for:
- dollars of damage
- dollars in damage
- dollars worth of damage
If we look to dictionaries for definitions of preposition "of" which fit the uses in your sentences.
3.used after words or phrases expressing quantities:
a pint of milk.
A1 used after words or phrases
expressing amount, number, or a particular unit:
a kilo of
a speck of dust
a drop of rain
I've tried finding an entry for preposition "in" to match the above structures, but couldn't find one. However, prepositions can begin adverbial phrases, such as in the following examples:
- I will sit [in silence].
- a pound [in weight].
- He is the leader [in name only].
If we use NGram viewer to see the results for:
a pound of weight
a pound in weight
We see that they have roughly the same frequency. As far as I can see, "in weight" is an adverbial phrase modifying "pound". In the case of "of weight", many would say this is a genitive construction, as in:
Where the rights are possessed by man. However in the case of "a pound of weight" it's a stretch or I'd say untenable to say that the pound is possessed by (the) weight. Luckily most definitions of the genitive case don't strictly limit it to possession, even though some mix up the two as being the same:
1. Of, relating to, or being the grammatical case expressing possession, measurement, or source.
American Heritage Dictionary
Regardless of identifying what constructions they actually are (I'm not exactly sure), to answer your question as to what the differences are among your four examples, I really don't see a significant difference.
Note there is a difference when saying a part of a whole. Notice how in this article it uses both "in" and "of" and notice when it does so:
That was $2.3 trillion in exports and $2.9 trillion in imports
of both goods and services.
More than 80 percent of
U.S. imports are goods.
Slightly less than a quarter
of imports are industrial machinery and equipment.
Services make up 18 percent of imports.
You notice it used "of" when talking about a part of a whole, such as a percent or a "quarter".
However when saying something like "x dollars in/of/worth of
imports/exports", you'll see all variations, and I don't see a difference in these cases:
President Trump announced Monday that he is ordering 10 percent
tariffs on $200 billion worth of imports from China.
U.S. finalizes next China tariff list targeting $16 billion in
Headline of Business Insider article
On Monday, President Donald Trump's administration announced it will
impose 10 percent tariffs on about $200 billion of imports from
China effective Sept. 24.
U.S. President Donald Trump has told aides he wants to move ahead on a
plan to impose tariffs on Chinese imports worth $200 billion next
Here four different news articles use each of the four variations you have in your examples. And you will find innumerable examples of these variations in a search. I very much doubt many people would claim that these mean different things, or that any are incorrect. At least that's what I think.
Note: I'm not saying I don't see any difference in general between these constructions, only that in the the specific contexts that you've provided I see little if no difference in meaning. Whether there's a difference among "a pound of weight", "a pound in weight" or "a pound worth of weight", my feeling about that may be more nuanced.
Hope all of that was at least some help.