
I don't see how there could be a conflict between these sorts of things and christianity. Perhaps the "hollow earth theory" is a little more far fetched, but the bible has a lot of strange things in it that indicates some sci-fi like things. A lot of things in there are described as what seam to be strange machines or space ships.
We also see a lot of similarities with modern humanoid visitors from outer space and ancient angels.
The strange abduction by reptilians and greys seam to parallel old accounts of demon encounters.
I think a healthy amount of scepticism is good, but there is some interesting things that I believe go right along with christianity on these types of subjects.
Seeds of thoughts one has to watch or your thoughts can wander and you feel justified in them as it was a slow curve to the left. One does have to be careful of that.
I have been doing a bit more reading and I am seeing more then a few tribes has ideas and stories on this concept of the interior being inhabited.