Are all atheists this ill-informed about religion?

[TheRocketSurgeon]

1) Nobody has explicitly invoked peripheral doctrines, at least from what I've seen. 
2) But in the real world, the vast majority of doctrinal diversity is, in fact, peripheral. 
C) So if these uneducated atheists are commenting about doctrinal differences, odds are, they are talking about peripheral differences. 

So where does this leave us? As I've said, most atheists here are too uninformed to draw the core/peripheral distinction. If they're talking about differences in general, they are likely going to be talking about peripheral differences. If you want to suggest they are talking about core differences, where's the evidence for it?

What part of the core doctrines do you think we either don't grasp, or don't address? For just a moment, we'll pretend that all Christian faiths agree with the Nicene Creed (here, I'm using the shorter Apostles' Creed; since you claim that the core beliefs are unchanging, you should have no problem with this), generally considered to enumerate all the core doctrines of belief, and see what you thin it is we don't know or discuss:

I believe in God the Father Almighty, Maker of heaven and earth.

This would be, oh, every single discussion we have on cosmology and evolutionary biology, and the complete lack of evidence for divine influence on what is now clearly a very natural process, even if we're not 100% certain of how two of the major events in this chain happened, yet. But hard to argue that we don't discuss it.

And in Jesus Christ his only Son our Lord; who was conceived by the Holy Ghost, born of the Virgin Mary, 

Good grief, I can't even tell you how many discussions I've seen over the ridiculousness of the claim of a God that has a half-God child, that a woman got pregnant and gave birth as a virgin (and including the fact that the prophecy to which they were referring, in Isaiah, to establish Jesus' sovereign claim in their story, is a total mistranslation of the word alma, for young woman, when Isaiah uses betulah, the actual word for virgin, several times... but not there), and so on.

suffered under Pontius Pilate, was crucified, dead, and buried; 

Mountains of posts on this subject, particularly regarding the historical evidence of Jesus (or lack thereof), including the claims regarding Pilate in Tacitus et al, and the writings of the early church fathers on the evolving view of this event.

he descended into hell; the third day he rose again from the dead; 

This one we don't discuss, much, though I certainly have seen the "rose from the dead" issue discussed.

he ascended into heaven, and sitteth on the right hand of God the Father Almighty; 

Not much to debate or discuss, here, other than the fact that none of the non-apostle "witnesses" to this ascension seem to have bothered to tell anyone, or write it down where it could become a testable early relic of the church prior to the 20-years-later crafting of the foundational documents of this religion.

from thence he shall come to judge the quick and the dead. 

Again, not much to discuss here.

I believe in the Holy Ghost; the holy catholic Church; the communion of saints; the forgiveness of sins; the resurrection of the body; and the life everlasting.

Since I'm not sure if you do actually believe in the holy catholic Church, I'll leave this one alone as potentially doctrinaire, but will note that the concepts of life everlasting and the forgiveness of sins are among the most common topics, here.

In short, if you have a different idea of what constitutes these "core beliefs" you speak of, and why we would or should discuss them in some manner other than our current discussions on these points, we're all ears... but if you're just going to sit there and claim we don't talk about core beliefs, but only doctrine, then you are clearly delusional.