Can I ask why? Why would you search for existential meaning? Why there? The book opens with a vengeful God putting babies to the sword, advocating the stoning to death of just about anyone who has sex without his say so, demanding sacrifices etc. What is it, after reading all that, that makes you think "I bet there'll be some great existential nuggets in here, if only I can get past all the blatant misogyny and homophobia and see the bigger picture"?
There's a great 'big picture' message in the Lord of the Rings too, but very few babies being put to the sword by the main protagonist - and it's got fight scenes. — Isaac
Initially, let's disabuse ourselves of the notion that ancient religion typically stoned people, at least not for the past 2000 years. If you want to use the biblical accounts as evidence that the stoning actually occurred, you would be taking a literalist approach to the OT and would be accepting is historicity. To prove the actual existence of stoning, you need a real historical source, not the OT.
The rabbinic view of the death penalty made its use so limited, that it was de facto impossible to ever occur. For example, the person who was committing the crime must have been instructed at the time he was committing it of the possibility of the death penalty and he'd have to acknowledge understanding it. The Talmud lists the last death penalty as having occurred in 28 CE. The exact date is debated, but we're looking at an ancient religion that was not quite as barbaric as you're suggesting.
https://en.wikipedia.org/wiki/Capital_punishment_in_Judaism
Regardless of that, you've asked a few questions I'll respond to:
Why I would search for meaning is in itself a teleological question, asking for what purpose would I make such an inquiry, which presupposes that meaning matters. So my initial question back to you would be why do you seek meaning in my behavior unless you're assuming meaning matters. But, to answer your question more directly, I want to understand the meaning of life because it's personally important to me for likely the same reasons it's been important to milliions of people over the past thousands and thousands of years.
I think Frankl answered this question better than me, describing the significance of the "will to meaning."
https://medium.com/mind-cafe/7-viktor-frankl-quotes-to-motivate-you-to-find-your-purpose-2ece0c64f1d8#:~:text=It%20was%20based%20on%20Frankl%E2%80%99s%20observation%20that%20those,find%20meaning.%20He%20called%20it%20%E2%80%98will%20to%20meaning%E2%80%99.
I look to the bible for meaning because there is a rich tradition over the millennia of scholars using it as a means to derive meaning and purpose. I can benefit from those efforts and that wisdom by reading what they've said. I also grew up in a Jewish environment, so the wisdom from that tradition comes to me with a higher degree of credibility than other sources, which is why people typically remain in the traditions they were raised in.
I'm not sure what you mean when you say that the book opens with God putting babies to the sword. That's not how it opens.
In any event, you are not limited to using the Bible to search for meaning. You could use the Koran, the Book or Morman, the New Testament, Dianetics, Lord of the Rings, Winnie the Pooh (which was attempted in
The Tao of Pooh), or even Green Eggs and Ham to find meaning and inspiration. I'm not claiming that all other traditions are wrong, but will admit to multiple paths to finding meaning. I do think if you choose the Lord of the Rings as your primary source of inspiration, you're going to be limited in terms of the scholarship you can rely upon for your learning and there won't be much of a community you can share your beliefs and discussions with. There's also the possibility you won't take your mission quite so seriously, as it's doubtful your identity will tied to the belief system of Lord of the Rings as perhaps a Christian's identity is tied to her belief. If your quest is the search for meaning, and you honestly have found it through the Lord of the Rings in a comprehensive way, I'd find it unusual, but I wouldn't think it impossible.
None of this is meant to excuse any bad conduct on the part of any religious group. Subjugation on the basis of gender, sexual abuse, physical abuse, or any other criminal behavior is criminal whether in the name of religion or not.