I noticed the word חֵטְא has an unusual spelling. I assume that in whatever pronunciation the Tiberian vocalization is based off of it was pronounced ḥēṭ with the aleph tagged along to show the relation to the construct forms. Surely /ħeːtˤʔ/ is not a possible pronunciation unless it was some kind of liaison situation. Is the shva related to the previous pronunciation or did they just add it to show it was a closed syllable? Was it originally (ie. pre-Hebrew) a two syllable word and if not why did it not get an epenthetic vowel like the segolates? If it was a two syllable word why does it not just end in a vowel like other words that used to end in /ʔ/?