Gotcha. I think. The first premise I presented is correct, then?
I think I find a few flaws with your later reasoning, though. I certainly understand that there are many atheists that do as you suggest -- tell people not to talk about God (not to be confused with telling people not to talk to them about God, which they have every right to do, and is very different from telling someone not to talk about God), and give the line about having "every right to believe as you choose, just don't talk to me about it." That's a very prevalent view on many message boards, as I'm sure we all know.
But to go back to the UFO analogy, having a problem with people who talk about UFOs isn't necessarily the same as having a problem with UFOs. They can, of course, coexist, but having a problem with the people who talk incessantly about the UFOs doesn't inherently mean that the person has a problem with UFOs. You can't have a problem with something you don't believe exists. I mean, if I don't believe in UFOs, how can they bother me? They can't. Their discussion could make me roll my eyes, since I may think it's futile to discuss them, but if I don't believe in them, that someone else does shouldn't really bother me. A very big and important "if." If it does bother or irritate me that someone else believes in something I don't think even exists, then it's likely that I may, in fact, believe in UFOs, and just have a problem with UFOs themselves, and therefore put up my little wall, hoping that no one will convince me that they do, in fact, exist.
Now, there are plenty of people who think those that do believe in UFOs are kinda weird (Fox "Spooky" Mulder, anyone?), but again, if that person really truly does not believe in UFOs, they would - if they were being rational - just shrug whenever someone started talking about UFOs and perhaps think, "Man, they're deluded."
There are many non-Christians and atheists who use the "just don't tell me about it" line, and I think they misunderstand the mission of a Christian. If they insist that Christians never tell them about Christ, and at the same time say that they don't care if someone is Christian, they're being oxymoronic, since sharing the gospel is part of being Christian. If they really meant what they said about "be Christian if you want," then they should, when a Christian shares gospel with them, say something like "Thank you, but I'm not interested." That's only respectful, and it's what I would do if someone tried to share the truth of UFOs with me. Okay, so I might listen to them blather for a bit, and tell them I don't buy it, but even that can be done respectfully.
I think those atheists that proclaim hatred for God (as opposed to a dislike for those who are aggressive proselytizers) aren't atheists at all. As I said, if they truly disbelieve in God, His mention should incite no more than perhaps a roll of the eyes and a feeling of pity for those who believe in something that doesn't exist (as I would any adult that still believes in the existence of Santa Claus, for instance).
But since I'm fairly sure that we're going with the premise that not believing in God is hating God, all of the above may be moot. Call it an exercise in insomnia. 8)