I agree with most of OP's points.
I remember back in patch 1, because ceremorphosis supposedly takes a week, in my very first run, I save scummed to finish almost the entire act 1 (up to freeing Halsin) with no long rests. That was A LOT of save scumming! What did that get me? Broken companion quests, loss of lore, and no tadpole powers. Thank Llolth barrelmancy was a huge thing! And stealth was so OP against the AI. I didn't even see the tadpole dreams! I'd been too afraid of using the parasite so my first Underdark sleep was dreamless. I finally found out from reddit!

Does a new player know that they shouldn't rush? NO. All the companion dialogue everyone here mentioned happens
over time. We were encouraged not to waste the time we had left by every person we met. IF we took them seriously, we would lack the additional info saying "hey, maybe our tadpoles are actually not acting like normal illithid tadpoles... maybe we're not actually changing into monsters just yet".
Fast forward to patch 8. Most classes get to use the tadpole on the ship, we get the first dream, we get more dialogue hinting that our problem is no longer so urgent... Awesome! The changes are subtle but very on point! Kudos to the devs. BUT Lae'zel still demands we act fast and unlike Shadowheart (who says, look for a healer... wow, thanks Shadowheart, that is so specific), Astarion (find someone who can control this thing... could you be more vague and unhelpful?), or Nettie (master Halsin was studying these things... he probably can't cure you, but might be able to tell you more... sounds dodgy, but thanks Nettie)... Lae'zel has a clear game plan: Find a creche. The creche has a zaith'isk - a purifying device especially crafted by the mlar, their most talented artisans -, which a caretaker will affix to the infected's head and quell the parasite. Although dodgy, this is the closest thing to a solution anyone offers. No ifs or maybes. And this is coming from the illithids' ancient enemies so you'd expect them to have some way to counter a 'biological weapon' like tadpole infection.
Sure, metagaming or trial and error will eventually give you more info - and better, easier paths - but what the OP said, from a narrative point of view, still stands. For people who haven't put 350 hours into EA like I have... a few more adjustments to Lae'zel's dialogue couldn't hurt.

Or if that's really something they don't want to change... adjust the actual fight. What's with all the extra attacks per round thing? What's with that number of hitpoints and that armor? Were they on sale? I want to buy me some of that... I pickpocketed Arron every day, I'm sure I could afford some of that super armor and uber HP. Even the lvl 8 cambions on the ship didn't have that... Suddenly all these gith mooks do? All of them? Random peon #4 is more awesome than Tav and Team? That makes Tav cry.