Is drift and sideslip angle the same in the accompanied figure?
The answer to the title question is no, sideslip angle and drift angle are not the same thing.  (in this figure, or any other...)
What the diagram shows is drift angle, and drift angle only.  If you are moving through a uniform airmass that is itself moving relative to the ground, your path across the ground (ground track, or course) will be affected by the movement of the air.  The difference between your heading (simply the direction the aircraft is pointing) and your actual ground track is the drift angle.  That is the teaching point, and purpose of this figure.
Regarding the numbered questions:

There is not enough information in the diagram to determine this.  Sideslip angle is the lateral angle between the relative wind and the longitudinal axis of the aircraft.  If the aircraft is in balanced flight, with the balance ball centered in the slip indicator, the sideslip angle will be zero.  It doesn’t matter what your heading is, it doesn’t matter which direction the wind is moving, or whether the aircraft may be drifting from its intended course.

The direction of the relative wind is always opposite to the direction the aircraft is traveling through the airmass.  In this example, presuming balanced flight, the relative wind is coming directly from the East.  If the aircraft was unbalanced, (balance ball out to one side or the other) there would be a sideslip, and relative wind would be striking against the side of the fuselage instead of head-on.  That angle is the sideslip angle.


There are different and better illustrations that show sideslip angle if you need more help understanding what it is.