Short answers, pulled from the story.
The earliest continuous Arabic text written in an ancestor of the modern script was carved into stone at En Avdat in Israel in 125 CE. This inscription predates the famous Namara inscription by two centuries and marks a turning point where Old Arabic began to take shape distinct from other Central Semitic languages.
Al-Khalil ibn Ahmad al-Farahidi lived between 718 and 786 and compiled the first dictionary containing all possible root permutations of the Arabic language. His work Kitāb al-'Ayn established rules for prosody and lexicography that shaped the classical tradition.
Maltese developed directly from a Siculo-Arabic dialect and remains the only Semitic language written with Latin letters today. It has experienced intensive contact with Italian Sicilian and English over eight centuries resulting in unique morphological features.
Ibn Manzur compiled Lisān al-Abd in 1290 containing 9,273 roots while Murtada az-Zabidi's Tāj al-`Arūs added another 11,978 roots by 1774. These lexicographers gathered instances of attested usage from poetry and Bedouin speech to compile the language systematically.
Khalil ibn Ahmad al-Farahidi fixed the Arabic script around 786 CE introducing diacritical points to distinguish letters like b t th n y. Originally scripts lacked dots until nuqa added them later followed by Tashkil signs indicating short vowels known as harakat.