It seems a number-transparent use of number can, in fact, take the when separated from it by some other word:
ii If [the same / expected number of people] come next time we’ll bring in
iii [Only the tiniest / stated number of people] have done a better job than
iv [The other / record number of mistakes she had ...
20% of the participants believes/believe that the world is flat
The noun "percent" (or just %) belongs with the number-transparent nouns like "lot" and "number", where the number of the whole noun phrase depends not on the head, but on the number of the noun that is complement to the preposition "of".
In this case, the complement of "of" is the plural noun ...
The word esoterics does not appear in Lexico (Oxford) online dictionary.
Esoteric is an adjective so it does not become a plural.
Esoterica is a mass noun, and doesn't really describe the oddities of language.
Your choice does not really fit, so I suggest your blank could be
I have yet to master its peculiarities.
Or more simply,
I have yet to ...
[The largest number of people] have applied this year.
I suspect the superlative largest is queering the deal here.
Last year's 50,000 applicants was well above average. However, the
largest number of people ever [have/has] applied this year.
To my ear, either have or has is possible, but I prefer has, probably because of the was in the first sentence....
Machinery used in an industrial or manufacturing process.
‘inadequate investment in new plant’
He's not referring to the place or facility where production takes place but the machinery.
huge concentrations of industrial machinery
To my understanding, the phrase change jobs represents an exchange of one job for another, it is plural because there are essentially two jobs involved in the exchange.
Similarly, an item can change hands from one person to another, or you can change airlines while traveling, etc.
A search in the Corpus of Contemporary American English shows 323 results ...
Try splitting the sentence in half and using the plural in both halves.
With complex sentences and in cases
when the types of sentences are unknown - use semicolons.
Sounds a little strange right?
Despite there being multiple, theoretical cases, in each case, we are concerned with a single sentence in particular. More importantly, the type of said ...