Conditional formula based on previous columns

This is probably a nice easy one... (three questions/parts)

Table of numbers.

1:
If values in column B = 0, colour green,
If values in column B > column A, colour red
If values in column B < column A (but <>0), colour amber

2:
How do I copy the above so the same rules apply in respective columns, i.e. B compared to A, C compared to B, D compared to C... I tried format painter with no luck (am I doing it wrong?)

3:
How do I colour scale the above formulae?
i.e.:
If column B is 0, colour green,
If values in column B ≥ column A, colour amber to red based on the previous values in that row
If values in column B ≤ column A, colour amber to green based on the previous values in that row

...and likewise copy to other cells