Is Tiberian Hebrew the version used for reading texts?

As a (non-Jewish) language and religion nerd, I've been learning Biblical Hebrew and I now know the alphabet and niqqud. There are a couple of things I don't understand about how some vowels are read. I've read and been told that qamats represents two different vowels depending on a number of rules, and I've read that segol represents a short ĕ and tsere a long ē but there are a lot of cases where segol is pronounced long, although it always has a silent letter after it. Tiberian Hebrew seems to have had eight different vowel qualities corresponding to the eight vowel signs (with a couple of exceptions), is there a reason why there are additional rules and interpretations added? Is it some kind of conversion between Tiberian and Babylonian pronunciation?