I suppose it's really two questions, on which I'll give my personal opinion while admitting that this is just the result of my thinking/speculation applied to DeWitt's version:
1 - What do I think Epicurus taught? In summary I believe that Norman DeWitt is correct about what Epicurus taught, as described in his chapter 13 "The True Piety." I especially think that Dewitt is correct in pointing to the description of the gods by the Epicurean Velleius in Cicero's "On the Nature of the Gods," and holding that Epicurus held that information about the gods comes from "anticipations" and through "images" and that these are not the same thing, and that this is reinforced and/or supported to the observational issues of "isonomia" and the eternal / boundless universe theory. In sum I think it boils down to Epicurus holding that in an infinite and eternal universe with nature never only a creating a single thing of a kind, and with there being an "distribution" from from "high" to "low," that Epicurus believed that there existed in the universe real beings who had achieved deathlessness and were self-sufficiently "happy" with their own existence.
If you think as Epicurus did that life exists throughout the universe, and you observe here on Earth that life exists on a spectrum from worms to humans, then it makes sense to project those observations to the universe at large and expect that there are unlimited numbers of life beings that are lower and higher than ourselves, all of which are natural, but some of which have attained things that humans have not, including deathlessness and total self-sufficiency. And to the extent that some life forms have achieved that kind of unlimited life with total happiness, that seems like an admirable result and something that we humans can consider to hold in admiration as a kind of goal that we intuitively all would like to emulate to the extent that we can. It's clear that Epicurus did not think that these beings have any involvement or concern with human life, but it seems that he may have thought it possible that "images" of them might be sensed in some where as a result of their images floating through the universe, just like all sorts of other images seemed to him to be floating through the air all the time.
I think all this is sort of a nexus / sum of real observations here on earth (the isonomia, no single thing of a kind, spectrum observations) combined with a logical extension of these ideas out onto the theory of the eternal / infinite universe with life throughout it. So these gods are totally NOT supernatural, totally unconcerned with us, totally NOT omnipotent or omnipresent or any of the other attributes of "gods" assigned by the general monotheistic cults. He was calling them 'gods' in the sense that we might call Michael Jordan a "god of basketball" - supremely successful at "life" but still totally natural. (And this is probably similar to how he used the phrase "gods among men" that something that sounds like a goal he considered attainable, or the way Lucretius described Epicurus himself as a god.)
And I don't think that Epicurus thought this was all just idle speculation. I think he thought that his observations about life on earth combined with the deductive logic of atomism compels this conclusion when it is all applied to the eternal / infinite universe, with life not limited to earth and having no beginning. He seems to have thought that we should be rigorous in applying our observations to their logical conclusions, and that this is part of what you arrive at when you think about life in the rest of the universe outside earth.
Hiram / others sometime refer to this as a "space alien" theory, but I find terms like that to be unnecessarily demeaning and dismissive to the theory. Now I wouldn't be surprised if some of the ancient Epicureans were tongue-in-cheek, such as the apparent position that they thought the gods spoke Greek, and so I am sure that some of them had fun with the theorizing and so you have to be careful interpreting the surviving fragments. But in general I think Epicurus thought the theory was very serious and logical and helpful, and it was in no way a means of protecting himself from accusations of blasphemy, a means of manipulating weaker minds, or even a type of honey to help sick minds. I think he thought that the idea that humans are the only life in the universe was very damaging, just like it would be damaging to think that the Earth was at the center of the universe (which would imply that it is somehow special / special to a supernatual god). It was therefore important to him to have a reasonable theory about how a spectrum of life exists throughout the universe, and that the top of that spectrum would be in no way supernatural. I think he fully believed it himself with the caveat that he knew that he didn't have all the evidence we'd like to have so that theories of how the gods lived in detail was just pure speculation.
2 - What is my personal opinion of what I think Epicurus taught? I think it makes very good sense to me, and in those times when I want to think about the subject of life existing outside of earth I think this theory is very helpful for keeping perspective on where humanity stands in the nature of things. I agree with Epicurus that I think the universe as a whole has always existed, and that life is not limited to earth, and that similar natural mechanisms will proceed an unlimited number of places when under similar conditions, so when I put all that together I think humans are just one example of life and that there are huge numbers of lower forms of life in the universe elsewhere, huge numbers of "higher" forms of life, but every one of then natural. I think among the benefits of having a theory of a spectrum of beings like this is that it helps us keep perspective that we are neither at the top of the heap (and therefore we're not the special favorite of some god) but then neither are we something to be dismissive of and commit suicide because we're not something that we're not.
Along the lines of other comments in this same thread, I don't think it's necessary for everyone today to subscribe to a theory like this. But I do think Epicurus was looking at providing for a system of thought for "the millions," and he thought that many people feel compelled to think about life in the rest of the universe and where we stand in it, and that this theory provides an answer that is both beneficial and reasonably expectable to be true. And I'm one of the people who thinks about issues like this, so I applaud him for developing the theory, and I find it helpful myself.