Is it a violation, an illegal screen, or nothing?

[assignmentmaker]

Is it a violation, an illegal screen, or nothing?

A1 is throwing the ball in. B1 is defending, in front of and facing A1, at the boundary line. A2 stands beside B1. A1 inbounds the ball to A3, then steps around A2 to come on to the court. Does this violate the requirement that a player legally out-of-bounds come directly on to the court? Is A1 expected to wait for B1 to get out of the way? Or go the slightly shorter path, around B1?

What if B1, guarding A1 who is making a throw-in, moves over 1-player width from directly in front of A1? A2 steps in beside B1 and is now in front of A1, making the shorter path onto the court that of stepping around A2. If it seemed like a violation above, does it seem like one now?

If there is no violation of the requirement to come directly inbounds from being legally out of bounds, what if B1's orientation is such that a line drawn between his or her feet is perpendicular to the boundary line? When A1 comes onto the court and B1 knocks into A2 turning to follow A1, has an illegal screen, outside B1's visual field, been set?