Hadith shows Quran is either imitable, not perserved, not clear

Muslims and the Quran itself insist the Quran is so great no chapter can be imitated by humans, even if a group of them came together and tried.

Say, "If mankind and the jinn gathered in order to produce the like of this Qur'an, they could not produce the like of it, even if they were to each other assistants."--Quran 17:88

Or do they say, "He has made it up"? Rather, they do not believe. Then let them produce a statement like it, if they should be truthful. --Quran 52:33-34

There are more instances where the Quran makes similar claims (eg. 2:23, 10:38, 11:13). The Quran, which insists its a clear book (11:1, 16:89, 41:3), gives no clear criteria for how to judge inimitability, which has caused different scholars to speculation on how it is inimitable. Regardless, whatever the case may be is not really relevant to this argument.

Another claim common among Muslims is that the Quran has been perfectly perserved, that is, it has not been corrupted, no verses have been lost. I am not aware of any actual Islam text
(other than commentaries) stating the Quran today is the same as that at the time of Muhammed's death (despite the fact variants like Ḥafs and Warsh). The following verse was taken by commentator ibn Kathir to mean the Quran cannot be added to subtracted to:

 But this is an honored Qur'an  [Inscribed] in a Preserved Slate.--Quran 85:21-22

as we see in his Tafsir:

(In Al-Lawh Al-Mahfuz!) meaning, among the most high gathering, guarded from any increase, decrease, distortion, or change. This is the end of the Tafsir of Surat Al-Buruj, and all praise and blessings are due to Allah.--ibn Kathir Tafsir on Sura 85:21-22

Likewise, Surah 6:115,

And the word of your Lord has been fulfilled in truth and in justice. None can alter His words, and He is the Hearing, the Knowing.--Quran 6:115

According to Tafsir al-Tabari, men cannot "add or delete from Allah's Books,"

The word of God meant in this verse is the Quran. This word is complete in truth and justice. Nothing can change Allah's word which he revealed in his BOOKS. The liars cannot add or delete from Allah's BOOKS. This is referring without a doubt to the Jews and Christians because they are the people of the books which were revealed to their prophets. Allah is revealing that the words they (the people of the book) are corrupting were not revealed by Allah, since Allah's word cannot be changed or substituted. --Tafsir al-Tabari, on Quran 6:115 (cited by Sam Shamoun and accepted by Bassam Zawadi, as I cannot get the source myself)

The claims that 1) the Quran is inimitable, 2) is perfectly preserved seems to be contradicted by the hadith.

There are sunnas that claim the Quran has missing verses, one of these is the following:

 Ibn Abbas reported Allah's Messenger (may peace be upon him) as saying: If there were for the son of Adam a valley full of riches, he would long to possess another one like it. and Ibn Adam does not feel satiated but with dust. 1413 And Allah returns to him who returns (to HiM). 1414 Ibn Abbas said: I do not know whether it is from the Qur'an or not; and in the narration transmitted by Zuhair it was said: I do not know whether it is from the Qur'an, and he made no mention of Ibn Abbas.-- Sahih Muslim, Book 005, Number 2285

 In addition to ibn Abbas, also Abu Harb said similar:

Abu Harb b. Abu al-Aswad reported on the authority of his father that Abu Musa al-Ash'ari sent for the reciters of Basra. They came to him and they were three hundred in number. They recited the Qur'an and he said: You are the best among the inhabitants of Basra, for you are the reciters among them. So continue to recite it. (But bear in mind) that your reciting for a long time may not harden your hearts as were hardened the hearts of those before you. We used to recite a surah which resembled in length and severity to (Surah) Bara'at. I have, however, forgotten it with the exception of this which I remember out of it:" If there were two valleys full of riches, for the son of Adam, he would long for a third valley, and nothing would fill the stomach of the son of Adam but dust." And we used so recite a slirah which resembled one of the surahs of Musabbihat, and I have forgotten it, but remember (this much) out of it:" Oh people who believe, why do you say that which you do not practise" (lxi 2.) and" that is recorded in your necks as a witness (against you) and you would be asked about it on the Day of Resurrection" (xvii. 13).--Sahih Muslim, Book 005, Number 2286

To this dilemma, some Muslims response either 1) yes, some of the Quran was lost,  or 2) No, the text cited by Sahih Muslim from ibn Abbas and Abu Harb is actually a hadith, not a verse from the Quran.

If 1) is true, it means the claim of perfect preservation is not true, seeming to imply both the greatest Islamic commentators ibn Kathir and al-Tabari were mistaken. Also, in turn means the Quran is not as clear as it claims itself to be since even the greatest Tafsirs got it wrong.

However, the more damaging path to take for a Muslim is 2) that ibn Abbas/abu Harb are mistaking it for a hadith. It would be better to claim the Quran has not been preserved without defect, that is this passage lost. The admission that these individuals mistook a hadith for the Quran demonstrates Muhammed's speech does resemble the Quran, making the Quran imitable, contradicting the Suras stating even a team of humans and jinn would fail.

In summary:

Premise 1: The Quran's states it is inimitable (2:23, 10:38, 11:13, 17:88, 52:33-34)
Premise 2: Early Muslims mistook a hadith for the Quran itself.
Conclusion: The Quran is imitable, contradicting its own claim, therefore the Quran is false.

or,

Premise 1: Parts of the Quran are missing according to early Muslim sources like ibn Abbas, abu Harb and Muhammed's child bride, Aisha.
Premise 2: The Quran states it is a clear book.
Premise 3: The top Islamic commentators of the Quran commenting on the Quran state that Allah's book cannot have anything lost.

Conclusion: The Quran is not clear since the top scholars misunderstood the Quran (unless the Quran was wrong too!) when the Quran claims to be preserved, therefore the Quran is false.