Sorry for the late reply .
My babies don't cry NATURALLY
They cry for a reason
That poop IS NOT NORMAL
Also I suspect baby is cold. He needs about 30C temperature. And moisture or you will burn his skin
I assume you are raising a clutch of caiques which is way different than raising a single caique from a previous owner who only fed him wet Cheerios.
And a full crop seems to be a generalized term what's full in your book could be a slightly stretched out crop for others. He has such an elatice crops since day one that he can go over 25 ml and will keep eating until his crop bursts. And I don't want to even play around with "well ehh that kind feels firm but it seems slightly soft still maybe he needs more food (25ml later)"
I've fed him by his weight as the avian vet instructed me to do so as well as other caique breeding guides.
Update guys:
He is reaching week 9 more or less could be off by a week ( last owner gave me a week estimate not an exact hatch date).
He now weights 150g
He is starting to tone down the screaming, very social now. Now he is fully feathered, but I am not sure if he is ready for a cage with a low perch and a sealed cardboard bottom. I tried it today for a while and he was already climbing the cage rails up to the very top but seemed to have trouble climbing down . So I took him out shortly after that. What do you guys suggest? He is way to active for the small old handmade brooder and I don't know if I can walk out for an hour or two with him being in the cage.