Number of Scripture citations is by no means a measure of truth.
However, there are aspects of this essay which I find troubling.
What exactly is meant by "will(ing) the Trinity"? Rather than taking the usual FR tack of seeing something I don't understand and hollering "UnBiBlIcAl!!!!!!! HeReTiC!!!!!!!!!", I'll ask. What does that mean?
Also, what is meant by: "Thirdly that Christs absolute predestination could not be "occasioned by sin" or even for the sake of men and angels."? I can understand that the Incarnation and Glorification of Christ have nothing to do with sin, but what does that say of the Sacrifice?
I suspect the author means the covenant of Salvation
Each member of the Trinity has a specific role. The Father creates and elects
The Son saves and judges
The Holy Spirit convicts, leads and teaches
Theologians employ a special phrase ("the economy of the Godhead") to describe the united operation of the three Persons. In whatever activity God engages, the three Divine Persons move in perfect unity, harmony, and cooperation. For example, Creation was the work of the Father (Gen. 1:1) by the Son (Col. 1:16; Heb. 1:2) through the agency of the Spirit (Gen. 1:2). Compare also Genesis 1:26-27. There was no conflict, difference of opinion, or disunity within the Godhead in the work of Creation. The combined operation of the Godhead is also displayed in the resurrection of Jesus. Scripture attributes Christs resurrection to the Father (Acts 2:24; Acts 13:30), the Son (Jno. 2:19; Jno. 10:18), and the Spirit (Rom. 1:4; Rom. 8:11; I Per. 3:18). Although the three Persons of the Godhead have their respective offices and distinct identities, yet a marvellous oneness and unanimity prevails.