Q1:

If the order for CW is:
1- 0101
2- 0110
3- 1010
4- 1001

Then just go through it backwards to go CCW.

For example, if it is currently at #2 (0110):
*) To step CW you would go to #3 (1010).
*) To step CCW you would go to #1 (0101).

Q2: I don't quite understand your question, I think you're asking what happens if the first step in the sequence (0101) does not correspond to the motor's current position.

This is a problem with stepper motors - There is no feedback so we must assume that it is in a known position and that when we tell it to step forwards one step that it is able to do so.

You could fit a rotary encoder onto the motor so that you always know where it is, or you could have a switch covering one part of the rotation - Rotate the motor in one direction untill you hit the switch and then you know where the motor is. You can then rotate the motor back so many steps and you can assume that the motor is in the position NumberOfSteps * DegreesPerStep away from the switch.

Does that make sense or am I talking nonsense ?