As for moving finger's much vaunted statement that theists are "forced" to believe in free will, at the very most it amounts to saying that anyone (divine or not) who instructs somebody else to live in some particular manner, thereby presumes some form of free will in the recipient.
That is, it has nothing whatsoever to do with theism, but has to do with whether or not normative statements are seen as meaningful statements.
And, it is certainly wholly irrelevant (because it is a truism applying to every normative system you might encounter) when gauging whether prescriptive religions has the morality based on ideas like individual agency/responsibility as a central concern or a peripheral concern.
Now, as to a less "simplistic" view concerning the motivations of the god-creature:
1. Either the God is morally fair in a human sense of the word, or it isn't.
If it isn't, then we certainly can't go on about it as if it were.
If it is, then a few requirements has to have been met:
a) Any divine ordinance as to what is right behaviour should be understood by humans to be just and fair, norms, that is, they themselves would agree to. The very least one must require, is that a divine edict has an explanatory note attached to it where the deity or prophet explains why the sanctioned behaviour ought to be sanctioned, on rational grounds.
b) As for the ultimate fates of souls, no action or attitude of theirs that cannot be regarded as ethically relevant can be a criterion for whether they are punished or not.
If either of these requirements is not met, then the God is to regarded as unfair.
2. So, is, for example, the Christian God fair or unfair?
Answer: Decidedly unfair!
As a prime criterion of whether or not an individual is to be punished or not, is whether that individual BELIEVES that Jesus is his saviour.
If he doesn't believe that, he is consigned off to eternal punishment, irrespective of his actual BEHAVIOUR in life towards other humans (and living things).
That is, to hold some BELIEF, an "action" with ZERO MORAL CONTENT is made into the most important criterion to decide the fate of the individual!
Any fairminded god would be forced to concede that when it comes to moral judgments, it is totally irrelevant whether or not a human worships him or, indeed, believes in him.
Thus, since the Christian God doesn't concede this, then, if we are to believe in the Christian God, we are forced to conclude that he IS unfair and beyond (beneath?) human comprehension.
3. Lastly, how can we then try to explain this "necessary belief"-element in Christianity?
As I've suggested, it is closely connected to the "inherited sin" concept, which again is closely related to the primitive idea of evil-as-filth, evil-as-a-stain, a concept of evil that is NOT related to issues like free will.