Okay, I don't remember the "deliberately". Dick's a friendly person, so it seemed rather natural to me.
He IS friendly and open, which is WHY this story reads so wrong to me, since the very notion of this plan should have anathema to him.
Obviously, since you find the premise of the story flawed, you're going to find his behaviour with the child at best insensitive, since he's not thinking about the future all that much; but I think it's worth keeping in mind that in the story he's at first attempting to unmask Emily and then protecting/proving her as an innocent, so in that way he's already being concerned about the kid. I'll need to reread.
Concern for the kid I can almost buy, it's his method of doing so I have such an issue with.
On the subject on them not sleeping in the same bed, I always thought Emily thought Dick was gay, and she respected that either he couldn't tell her either he hadn't admitted it himself.
Ummm... she's already MARRIED him, I sincerely doubt she thought he was gay. Or if she did, what the hell does that say about her?
It made a lot more sense to me than their abandonment issue discussion. (About your mention of Emily being needy: that scene was the closest the story came to stating it, but I thought that discussion made it fairly obvious. So it's implied at that point.)
If you mean the "other secrets" bit, I didn't get the slightest trace of gay subtext there, she'd just found out that the man she married had lied consistently about their very marriage status, which way he swings is almost irrelevant compared to that.
I found it easier to imagine that Emily was having issues with sex so soon after the loss of ANOTHER husband (though clearly NOT with marriage) and Dick was using that to come across as being solicitous to her feelings.