The first thing to note is that my theology implicitly suggests a separate temporal dimension for 'God-time', since God's consciousness jumps back and forth in physical time, reliving the same physical time-periods over and over from different human perspectives. Any such time-travel presupposes a separate dimension of time for the traveller, for how else can we make sense of the claim that he experiences the physically-earlier moment after the physically-later one? The scale we measure this against obviously is not the scale of physical time.
Now, on to Blar's objections:
One concern is that your theology may entail a kind of partial predestination. I am God now. Out of the 6 billion people in the world, my best guess is that about half of them have already been God. Every aspect of my life that influenced the 3 billion people who already lived must already have been determined before I was born... Sequential God-lives create a similar problem with respect to morality... It is not clear that morality/rationality says that you should care about making your past life better, and, depending on how your theology deals with the problem of causality and partial predestination, it may not even be possible.
The implication is that we/God (seemingly) should not care about anyone older than ourselves, since their entire life has already been and gone in God's experience. We should only care about younger people, since those are the ones which God/us is yet to live through.
To avoid these problems (of predestination and moral rationality), we should take physical time as fundamental. Divine time emerges out of this, by "replaying" periods of physical time from a new perspective.
What this means is that the apparent temporal orderings are merely illusory. It is not the case that the first person lives their whole life and makes all of their causal contributions to the world before the second person gets to do anything. No. Physical contemporaries are genuinely contemporary in their causal impact. The lexical ordering (whereby God makes all of his choices as person 1 before making any as person 2) only occurs within "God-time": that is, the ordering of appearances within God's consciousness. This has no impact whatsoever upon the physical universe. Physical time behaves normally.
Let's clarify this with an example. Suppose young Biff is choosing whether to hit old lady Sue. In physical time, Biff's violent decision A occurs before the event B of Sue getting hit. Whether or not Sue gets hit depends upon Biff's decision, just as we would normally expect: A causally influences B. By contrast, God will experience the outcome B (as Sue) before he experiences the making of the decision A (as Biff). However, it is the former dimension of time that is fundamental.
Blar worries that the order of God's experiences suggests that B is fundamentally prior to A. Once B happens, and happens "first", then A is predetermined. Once God is conscious as Biff, he is forced by fate into making violent decision A. Alternative possibilities are not open to him. That is the concern. (The point is stronger if we assume incompatibilism between free will and determinism.)
But it gets things backwards. Once we make physical time fundamental, these problems disappear. A causes B, not vice versa. A is not predetermined by B. Although God experiences B first, that is just the order of appearances in his consciousness.
It is a proven fact that orderings in "experienced time" can diverge from the objective (physical) order of events -- see here. In the discussed "cutaneous rabbit" experiment, whether one experiences the second tap as on their wrist or further up their arm will depend upon where (and whether) subsequent taps occur. The (objectively) later event affects our (subjectively) earlier consciousness. I am suggesting that God-time is like this. Whether God-as-Sue experiences B (the subjectively earlier, but objectively later event) will depend upon whether he-as-Biff makes the violent decision A (the subjectively later, but objectively earlier event).
So it is still rational to be nice to older people. If God-as-Biff hits Sue, then that will cause God-as-Sue to feel pain, even though God experiences being hit (or not) subjectively-before he-as-Biff makes the violent decision. If Biff chose a more peaceful path, then he would avoid the subjectively-earlier sensations of pain (experienced when God is incarnate as Sue). I hope by now it's reasonably clear why this is indeed coherent.
I think my elaborations here successfully counter Blar's objections. If he agrees, I look forward to him converting to my religion -- which, by the way, needs a name. Any suggestions?
One final point of interest: We may in fact need at least three dimensions of time. I noted above that the time-traveller and the cutaneous rabbit both involve temporal dimensions distinct from physical time. But they are also distinct from each other. The time traveller's temporal dimension is objective, like the physical. It could even apply to molecules, for example. (The time-travelling molecule goes backwards through physical time as its traveller-time progresses forwards.) The cutaneous rabbit, by contrast, involves subjective time which is inherently representational. A molecule could not have subjective time. It has no 'order of appearances', since it is not conscious and so is not "appeared to" by anything.
But one might plausibly deny that subjective time is really time at all. It is rather the appearance of time. (When I say 'order of appearances', I really mean 'the appearance of an ordering'.) This could simplify my theology. We could simply deny that the God-lives are really sequential. Rather, they appear to God as if sequentially. God seems to live all of person 1's life, then all of person 2's, and so forth. But there isn't really any time-travel going on here. It's just an illusion, a representation of temporal orderings, nothing more. If one further denies the possibility of time-travel, then we are back at the standard one-dimensional view: the only time is physical time.
Actually, there's more: only eternalists can be one-dimensional about time. If you're a presentist and believe that there is a "moving 'now'", an ever-changing one-true-present, then you are committed to infinite temporal dimensions.
For what is the 'now' moving through? Clearly not physical time, as that is instead what it moves along. To see the difference, suppose that the moving now started moving backwards in physical time. That is, it moves from 14 July, to 13 July, and so forth. As the 'now' progresses (along what?), it goes backwards in physical time. The "along what?" dimension cannot be physical time, because that is regressing, not progressing. It must be some meta-time: a 'traveller-time' dimension for the 'now' to move along.
This then threatens infinite regress, as one can raise questions about what the 'now' is moving through as it moves along meta-time. We seem to require a meta-meta-time. And so forth. (I think this argument is from McTaggart. It was discussed in philosophical logic class today, anyway. Fascinating stuff.) So I'd recommend ditching presentism - again - unless you're willing to accept an infinite number of temporal dimensions.