I just want to preface my response by saying that I studied under Rabbi Artson, and I have great respect for him: he is a mensch and a fine scholar.
But I disagree with him very much in regard to his theology.
To be fair to him, I think there are elements of pure process theology that R' Artson, in his particular theological work, modifies and reshapes. I think, for example, the way that he deals with reality is not quite as an ultimately insubstantial series of events; I think-- though I could easily be in error-- that he would probably say that it was more of a melding of material phenomena and mental/spiritual phenomena.
Also to be fair, I don't think there's any question for R' Artson that Jews should be observant. He has always been crystal clear on that point. And while I am not sure he would invoke the authority of scripture, per se, he would and has certainly been quite clear on the importance and authenticity of rabbinic authority, which in some ways boils down to the same thing.
However, I think your questions as to reconciling elements of process theology and rabbinic thought and tradition are entirely fair questions, and I have never been able to see effective answers for them. Nor have I heard any from R' Artson. Perhaps in the years since I studied under him, he has come up with such answers-- I don't know.
But at least when I was hearing him speak, I felt that he never offered good answers. It always seemed to me that for R' Artson, he needed process theology in order to establish a theology wherein God was truly omnibenevolent, yet acknowledged that evil and suffering exist within the world. In order to achieve this, he sacrificed God's omnipotence in favor of omnibenevolence. While I understand that many process theologians attempt to depict the God of their theology as still sort of omnipotent, since (as you note) they claim that the classic conceptualizations of omnipotence necessitate God being the primary and direct actor of all actions. However, I think this argument is a straw man-- a large number of scholars in Rabbinic tradition (and, for that matter, some schools of thought in other Western religions, also) characterize God as omnipotent but do not depict Him as the primary and direct actor of all actions. So it really does boil down to either God being omnipotent or not.
And while I understand why R' Artson would wish this, I find such a theology entirely unsatisfactory. To me, if God is not omnipotent, not omniscient, not truly capable of everything, then I fail to see why He is God. Though it is, emotionally, a harder theology, I would far rather that God be omnipotent, but not omnibenevolent. Which is not to say I don't believe God is basically good-- only that He is not solely and essentially God. I think God is basically good, but that-- from our perspective, here within this plane, this life-- can be ruthless sometimes, sacrificing the immediate good of individuals within specific lifetimes on earth in favor of more overarching, long-term good for the universe or humanity as a whole or the Jewish People as a whole or so on and so forth.
For R' Artson, that's a dealbreaker, a no-go. For him, God must always desire only good for every individual, and be willing to do His best to make only good for every individual, but-- because of the reality of evil and suffering-- be unable to ensure only good for every individual.
For me, however, such a God is no God at all, as I cannot conceive of worshipping anything so imperfect, so ineffectual. I also have trouble with the idea of God changing and evolving in the sense that process theology demands-- to me that seems entirely contrary to God's eternality and omnipresence. But honestly, that's hugely secondary to the omnipotence issue.
Some of the other elements of process theology, though, I have no problem with, given the proper recontextualization and adaptation. For example, something approaching or roughly analogous to theocosmocentrism is found in Lurianic Kabbalah-- although that's also, in its most refined form, essentially a kind of monism, which sort of negates the theocosmocentric aspect of it. Likewise, in terms of free will, I might characterize the universe very similarly to what you described above, with the key difference being that it is not that God "cannot totally control any series of events or any individual," so much as that God chooses not to totally control any series of events or any individual. This goes back to omnipotence, and the mischaracterization of it in process theology: omnipotence is just that, that God has the power to potentially do anything. It does not necessarily follow that God does do everything He is capable of. He may well choose not to do things, if He has good reasons not to do so.
In any case, process theology-- even in R' Artson's adapted form-- leaves me wholly unsatisfied. And, for what it is worth, I have heard R' Elliot Dorff (shlit"a), our movement's greatest philosopher and one of our finest poskim, make similar critiques of R' Artson's theology, though of course with great respect and collegiality.
Is it compatible with Conservative Judaism? It would probably be hard for it not to be. The range of theological options just within traditional Jewish thought is considerable; historically, as long as one observed the mitzvot according to the halachah, our tradition has given vast space to toleration of philosophical and theological differences. In a sense, that is still the case: if one follows the mitzvot, one's philosophical motivations are to a great extent irrelevant. And since we have long recognized that everything we may speculate about the true nature of God, once stripped of anthropomorphisms, metaphors, analogies, imagery, and so forth, amounts to nearly nil in the face of the ineffability of Ein Sof-- at least from our perspective, within this plane of existence-- there is little reason to suppose process theology to be any ranker a heresy (or the reverse, I suppose) than any other theology.
But I must say that personally-- disregarding, for the moment, the halachic minimums of observance as our primary standard-- I think the problem is not the compatibility of process theology with Conservative Judaism, but with any traditional Judaism, or any kind of even vaguely traditional conceptualization of God as both ultimate and personal-- to say nothing of covenantal.
But of course, R' Artson would say very differently.
