You asked about the vowel points in the Hebrews language, the claim by scholars that they were added in the early Middle Ages, and the question whether this would make them inspired or not. I will see what I can do to help you with this issue. The Hebrew vowel points raise a couple of issues. However, from my research I am convinced that the scholars have their origin right. Crude vowel points began to be used around the sixth century after Christ. They slowly developed until the present system was solidified around the tenth century and it became the system used by the Massoretes (and modern students of biblical Hebrew). According to the sources, it has been established that Jerome (345- 20AD) and the Talmud (completed around 500AD) knew nothing of the vowel points. Also, from shortly before the time of Christ, the history of changes in the writing of the Hebrew language can be confirmed through surviving commercial and legal documents. There is no cause to reject the claims of the scholars on this point.
However, as you mention, this brings up the issue of inspiration. According to the McClintock and Strong Bible Encyclopedia (Volume IV, p.137), the "origin of the vowel-points is to be ascribed to the effort which the Jewish learned men made to preserve the pronunciation of their sacred language at a time when its extinction as a living tongue endangered the loss of the traditional memory of its sound." Therefore, the vowel points were for the purpose of pronunciation. This pronunciation was understood and kept in collective Jewish memory as long as Hebrew was a living, spoken language. However, as its spoken use began to disappear, Jewish scholars determined to preserve this pronunciation by use of vowel points.
Much is made of the necessity of vowel points for correct understanding of the Bible text. I am certainly not a Hebrew scholar, but some things I know about the language make me question this. Modern Hebrew signs and newspapers do not use vowel points. Now that Hebrew is again a spoken language, it seems that the vowel points do not carry the importance they did when it was only a language of religious texts and services.
Are they sometimes necessary in order to identify a word? Certainly they help. However, even in English, we have words that are spelled the same way but are pronounced differently and have different meanings. They are called homonyms. We get along quite well without vowel points as did the Hebrews of years gone by. In most cases, as in English, the Hebrew meaning is quite identifiable by context. If I say, I put a bxt in my pocket, and a bxt can be either a car or a billfold, we can easily tell which is meant by context. Are there exceptions to this, places where the context does not answer the problem? Certainly. But that is a problem in straight definition too. Some Hebrew words are used only once or twice in the Old Testament and are unknown elsewhere. How do we know the definitions? We look at all of the evidence and trust God to lead to His true meaning.
As to the inspiration of vowel points, I think that we have limited God too much to the original copies of the scriptures. No, I do not teach a process of repetitive inspiration. However, I do not believe that God took His hands off of the process as soon as He unloaded one correct copy of His truth to the world. We are theists in theology and totally reject the deistic teaching that God simply created the world initially and then left it to its own devices. However, I think many are deistic in their doctrine of scriptural transmission. I think the solution to this gap is to develop a full concept of the preservation of scripture. Inspiration without preservation stills leaves us with no authoritative copy of the scriptures.
If inspiration is (this is my definition) the act of God by which He made every word of Scripture completely without error and completely what He wanted, then preservation is the act of God by which He keeps and protects the Word of God so that every word is exactly of His choosing and completely without error. Preservation may include transmission of God's word into another language. It may even include the adding of italicized words to fill in the gaps where one language understands certain meanings and another language puts these meanings into words. It may also include the adding of vowel points in order to preserve a common pronunciation that is disappearing as the language becomes unspoken among common people.
Are the vowel points inspired? I have no problem seeing them as such. However, if this is too difficult for you to conceive (seeing as how they were not present in the originals), then perhaps you can look at them as I do at verse and chapter divisions. I am not prepared to call them inspired. However, I do consider them to be providentially placed. They were put there by the providential hand of Almighty God. They can be accepted as true even though they were not a part of the originals.