Using these two scenarios which mother harms her child the most.

1.A heavy 3 pak a day smoker who smokes from the time she is
impregnated  and 9 months later the day the baby is born she finally
quits.
	                          OR
2.A mother who does NOT smoke during pregnancy but the day her child
is born starts smoking 3 packs a day for 9 months, transferring the
nicotine to her child by her breast milk.

We will assume that second hand smoke is not a factor.  

This third question is not required for payment but do you have any
ideas that States can take a child away from an unfit mother if the
child has excessive nicotine in its blood test?

Hi...

As a long time smoker ( and not a researcher )..I gave birth to
2 kids who are now smoke free....

Not sure how much this will validate your research however...

Nicotine itself has not shown significant detrimental health problems.
 The big problem is, however, the smoke from the cigarettes.   One of
the consequences of smoking while pregnant is low birth weight, so I
would submit that smoking while pregnant poses more harm than starting
to smoke after pregnancy and breast feeding.