It is best to establish a coordinate system with A as the origin, AB as the X axis and AP as the Z axis.

Using vectors to solve problems, we can solve problems quickly through the operational relationship between vectors, without considering what auxiliary lines to do.

So: A (0 0,0,0), B (2 2,0,0), D (- 1, √ 3,0), C (1, √ 3,0), P (0 0,0,2).

So the linear PC equation is: x/ 1 = y/√3 = (z-2)/(-2), so the vector BE(x-2, √3x, 2-2x).

(1) Since the Y axis is perpendicular to the plane PAB, the sine value of the angle between BE and the plane PAB is √3/4, the cosine value of the angle between BE and Y axis is √3/4, and the unit vector of Y axis is (0, 1, 0), then: (x-2) * 0+√ 3x. +3x？ +(2-2x)？ ], x= 1/2, then e (1/2, √ 3/2, 1) = (p+c)/2.

(2) For the vector BE(-3/2, √3/2, 1), the equation of plane ABE is 2y-√3z=0, and the equation of plane BEC is √3x+y+√3z=2√3.

Then the cosine of dihedral angle A-BE-C is: (0 * √ 3+2 *1-3)/(√ 7 * √ 7) =-1/7, and the angle is: arccos(- 1/7).