147: There are a lot more nuschaos then that. And 200 years from now nussach Artscroll will be a legitimate variation too!
Havara: Isn’t that closer to a patach? A better illustration would be Kamatz gadol == the “u” in “thump” kamatz katan == the”O” in Go.
For the Cholom, you missed the third pronunciation. The Yemenite cholom which is halfway between our segol and tzerey which is also the linguistic ancestor of the litvishe Cheylem.
BTW, you haven’t yet answered me about Yom Ha’atzmaut and behab. I know what Rav Tzvi Yehuda did. What is the common practice?