This comment is a literary masterpiece! It was a joy reading it.
I'm gonna try to answer some of your questions without spoiling it too much. Anyone reading along, I recommend playing the game first:
On the tad one-liners:
The other tads pick random lines from six different lists:
There's a default list, most lines you'll see will come from there. It contains all the normal chitchat that isn't tied to any particular situation, but it does contain some of the general hints.
Some events cause a different list to become active and make the other tads pick a message from that list immediatly. That's why, if you pay attention, you'll see shocked reactions from other tads when someone is killed in front of their eyes, or you see them screaming when a predator is chasing them.
When you lay an egg, a list is triggered that either calls you out on your bad parenting, or compliments finding a good hiding spot. New tads briefly have their own dialogue list, but they grow out of that in like a single frame.
At last there is one line that overwrites all others, when you are big enough, the bottom prompt for egg laying will show, the first time you run the game in a single session. Reading your comment, I realize I should probably also make that mention C/Z for people not already familiar with pico8.
On the predators:
The "urchins" jump at you (or everyone else) when they hear you.
Most predetors also have a hunger system, so if you ever find one chilling, it's probably still full from eating one of your pondmates. (they get tired too)
Lillypads don't help with eggs, because they only conceal from above, You need to find something that conceals from all sides.
Hope this information was interesting without spoiling the hidden mechanics too much.
Is Jeremy still doing well?