Free will is actually defined as voluntary tendency of movement toward union with a desired result. In the course of that movement, optional “paths” of attaining the union can present themselves to someone who is in process of attaining the desire.
The actual “opposite” of free will would be involuntary actions (forced actions which have no relation to reaching union with a desired result). The actions of a slave to satisfy his master often fit in that description (yet even there the slave may love his master and seek his master’s wishes voluntarily).
As far as God is concerned, involuntary works would mean works which he must do of necessity, where he has no desire to do them but his nature requires it. In actuality with God, he desires everything he wills and everything he accomplishes, and he desires every step along the way to be as it is. Therefore his act is voluntary and therefore free. There is nothing with God that contingently surprises him and appears in front of him as alternatives, such that he would be faced with a decision of “better or worse choice”.
As to the meaning of “God is good”, that simply means he is desirable; it is ultimately desirable to be united to Him to fulfill our own being. “God is good” has nothing to do with God doing things that are pleasing to our sensibilities. “God is good” also means there is no deficiency in God, but he is fully actualized, and not in process of becoming. Your phrase “God is evil” is a contradiction in terms. Evil is deficiency of actualizing oneself. It means that your “being” is not conformed to your potential but is ordered contrary to your potential, your “form”.
In point of fact, God does not “decide” things, but simply “knows” all and wills all that is, in full freedom of his fulfilled desire (his love of himself and of his creation).
