You are almost completely wrong. How do you account for the precision of Panini as the previous commenter pointed out? How do you know to postulate that? There is NO other formalized grammar akin to Panini, so don’t judge Samskruta by other so called Indo European standards!

What are you talking about? Panini did detail the pronunciation of each character. And the actual pronunciation (i.e. accounting for things like assimilation) is then encoded in the writing via Sandhi.

Likewise, we have older information on pronunciation as well in the Pratishakhyas.

Ancient Indians cared a lot about accurate pronunciation, especially for mantras where the thinking was that without correct pronunciation, the mantra would not work. Picture the Harry Potter "wingardium leviosa" scene.

Modern don’t actually hew to the prescribed pronunciation for certain letters, but it’s certainly specified by Panini.

That’s actually the first thing you learn and it’s quite rigorous where to vocalize and how.

Maybe if more people learnt the language instead of crusading on about it's supposed heritage, it would have been the official language of India.