You complain about my “curious choice of words” but then change the location of my negative so that the choice of words is no longer mine, but yours. I said that Denton was “explicitly not a Christian”, which has a different meaning from “not explicitly a Christian.” So your question “But is he a Christian in private?” is based on an error that you introduced.
One doesn’t need to make an educated guess, since he clearly indicates that he’s no longer a Christian. And by “based on his other output”, what “other output” are you referring to? What works of his have you read in which he directly or indirectly expresses his religious convictions? You need to specify, if you’re making a claim about what he thinks based on what he has written.
This is not relevant to determining what he thinks. Darwin’s ideas were popular among people who believed in compulsory sterilization of “the unfit”, but it does not follow that Darwin endorsed compulsory sterilization of the unfit. If you are trying to determine what an author thinks, you must base that determination entirely on what the author says, not on how some other reader interprets the author.
You misunderstand or misuse the terminology you are employing. There is no warrant for inferring that, because the universe was designed for human life, the designer must be a “personal God.” In Bible-based religion, the phrase “personal God” means something very specific; it means a God who communicates with individuals. There is nothing in Denton’s description of the design of the universe that implies any personal communication between individual human beings and God. There is nothing in Denton’s description of the design in the universe that requires anything beyond Deism, so I gather that you don’t understand what Deism is.
As for whether or not Denton is a “theist”, that depends on what definition you are using. If you are using the term narrowly (as it is most often used nowadays), to mean one who believes in a “personal God” to whom one prays, from whom one seeks guidance, etc., then there is no evidence that Denton is a theist. If you are using the term more broadly, and mean only that he affirms some sort of God who set up the universe to sustain life, including human life, then you are using “theist” to mean nothing more than “Deist”.
And in fact, his God appears to be even less directly active than the God of Deism; the original Deists thought that God directly created man, whereas Denton supposes that God directly created only the first matter, laws, and constants, with man (or more generally, intelligent life) emerging by development from the initial creation. So Denton’s view, as expressed in, say, Nature’s Destiny, is a sort of ultra-Deism, where God is even more remote from us than in the original historical Deism. Which, needless to say, is not Christianity, and not a Biblical view of things.
Denton is in no sense a Christian apologist. At best, he offers a view of the world which is compatible with Christianity, a minimalist “creation” doctrine which is nowhere near sufficient to get one to Christianity. And his view is equally compatible with Judaism, Islam, and even versions of Hinduism (“Hinduism” is not one thing, but a sort of anthology of religious and philosophical views), as well as with non-revealed “religion” such as Deism. So he’s no more an apologist for Christianity than for any of those other positions. His view is also compatible with just plain agnosticism, i.e., with believing that there seems to be something analogous to a mind behind the properties of the universe, but that we can say little about that “mind” other than that it has some tendency to express itself in the form of organized matter. Again, that’s weak stuff if one is trying to paint him as a religious apologist.
Why people who have not read any significant amount of Denton’s writing (which appears to apply to just about everyone posting here, other than myself) would try to make out that Denton has “creationist” religious motivations is a puzzle. I would guess that the motivation is political; Denton has affiliations with Discovery, and since the operative rule here is that anything and everything associated with Discovery must be discredited as Christian apologetics, Denton must be regarded as a Christian apologist, too, whether he actually says anything that would warrant that conclusion or not. We see this in Faizal’s repeated insistence that Denton is a creationist. Since, according to Faizal, everyone at Discovery is a “creationist,” Denton must be one, too, even if his thought lacks the two crucial defining features of “creationism” (i.e., Genesis literalism and denial of evolution). The goal is not to understand Denton’s position, but to smear Denton using guilt by association arguments. I presume that your willingness to speculate about hidden private beliefs of Denton, against his explicit statements, has the same political motivation.