It depends on the breed and the situation, so you absolutley MUST discuss this with your veterinarian. There is no other source that can offer you this information.
You can touch once in a while, but don't hold a kitten that young. The kitten can't see and relies on scent. You do not smell like the kitten's mother cat.
I would say none, the young kitten will probably not be able to cope with antibiotics and you would probably kill it.
no
yes
there are spacial kitten foods.
I have a 5 week old kitten that my fiancée and I rescued and he's healthy at 1.3lbs
A 4 week old kitten's eyes are not supposed not to be small since they open up by the second week hence they are becoming big.
take it to the vet
Kidney stones
from its moms milk it
Yes it is,its best not to give your kitten hard food when its to young,it can choke.but as long as the food is moist,it should be fine.
if your kitten is bleeding from his "bum" he is sick and should go to a vet
It depends on what breed of cat.