Does a reprehensible pause [when reading Qur’an] lead to kufr?

These words, in the general terms mentioned in the question, are clearly incorrect and are definitely contrary to the practice of the Muslims and all the imams or leading scholars, which is to quote part of a verse in their writings, lessons or khutbahs, without necessarily having to quote or write the entire verse as it appears in the Mus-haf. Rather they limit it to quoting of the verse only the part that is relevant to the context and relevant to the meaning they are trying to establish, so long as what is quoted of the verse is clear and readily understood.

If what you say is something that was said by one of the religious scholars, then he could not have meant it in general terms referring to all kinds of pause, as the questioner understood it. The only way we think he could have meant it is that what he was referring to was a type of pause that is reprehensible, as in the case  of a reciter who comes to a verse such as that in which Allah, may He be exalted, says (interpretation of the meaning): “So know (O Muhammad (blessings and peace of Allah be upon him)) that La ilaha ill-Allah (there is no god but Allah), and ask forgiveness for your sin, and also for (the sin of) believing men and believing women. And Allah knows well your moving about, and your place of rest (in your homes)” [Muhammad 47:19], and he recites “there is no god” then pauses there, without any good reason that would compel him to pause there, and without resuming the recitation by repeating some of the words in such a way as to make the meaning clear and make the context of the words understandable. 

Pausing in such a manner is blameworthy and extremely reprehensible, as is quite obvious. Whoever does that deliberately, intending to convey that distorted meaning, is undoubtedly a disbeliever. 

There are also other kinds of blameworthy pauses that corrupt the meanings of the words or give the impression of a meaning that is not intended by the text. 

Az-Zarkashi said in al-Burhaan fi ‘Uloom al-Qur’an (1/352-353): What is reprehensible is that which leads to the meaning not being understood, such as saying “al-hamd” [on its own]; there should be no pause on this word, or on any word without its adjective or predicate.

Even worse than that is pausing on phrases such as “Surely, they have disbelieved who say” [al-Maa’idah 5:72] (because the following phrase is “ ‘Allah is the Messiah (‘Eeesa (Jesus)), son of Maryam (Mary)’”) and “And if any of them should say” [al-Anbiya’ 21:29] (because the following phrase is “ ‘Verily, I am an ilah (a god) besides Him (Allah)’”); or starting from phrases such as “Allah is the Messiah, son of Maryam (Mary)” [al-Maa’idah 5:17], “Allah is the third of the three (in a Trinity)” [al-Maa’idah 5:73] and “Verily, I am an ilah (a god)” [al-Anbiya’ 21:29], because it is impossible for the meaning to be correct if you begin in this manner. Whoever does that deliberately, intending that (distorted) meaning, is a disbeliever. 

Similarly reprehensible is stopping at the following phrases: “So the disbeliever was utterly defeated and Allah” [al-Baqarah 2:258], “For those who believe not in the Hereafter is an evil description and for Allah” [an-Nahl 16:60] and the like, or “and if there be only one, for her is the half and for his parents” [an-Nisa’ 4:11] and “Only those will respond, who listen and the dead” [al-An‘aam 6:36]. 

Even worse and more reprehensible than that is stopping on a negation without completing the idea, as in the following examples:

“There is no god but Allah”

(pausing after the phrase “there is no god”, without completing the sentence, is wrong)

“And We have sent you (O Muhammad (blessings and peace of Allah be upon him)) not but as a bearer of glad tidings and a warner”

[al-Isra’ 17:105]

(pausing after the phrase “we have sent you not” is wrong). 

Also, pausing at the end of the following quotations is wrong:

“Allah has promised those who believe (in the Oneness of Allah – Islamic Monotheism) and do deeds of righteousness, that for them there is forgiveness and a great reward (i.e. Paradise) and those who disbelieve…”

[al-Maa’idah 5:9-10]]

“Those who disbelieve (in the Oneness of Allah, and in the Message of Prophet Muhammad (blessings and peace of Allah be upon him)), and hinder (men) from the Path of Allah (Islamic Monotheism), He will render their deeds vain, and those who believe…”

[Muhammad 47:1-2].

If the reader has no choice but to stop in order to take a breath, that is permissible, but then (when he resumes reading) he should go back to the phrase that came before it and connect it to what comes after it, and there is nothing wrong with doing so. End.

See also the answer to question no. 206946