That site doesn't look like anybody lived there. Neanderthals were not neat housekeepers. The traditional places where Neanderthals were found had stuff scattered all around.
The Neanderthals were good hunters, there is a lot of evidence that they hunted big game. They probably caught smaller game when it was available, but a rabbit doesn't feed a family nearly as long as a mammoth (sorry, I said mastodon, I meant mammoth). Also they wouldn't be as much available during winter, or a glacial period.
As far as the depth of the cave is concerned, that is not really germane. They were found about 1000 feet into the cave. That is the main thing, how deep it is doesn't really count. The distance from the entrance is what counts.
I notice in the link you provided that some people are considering that the 'structures' might be naturally occurring. The reason there is some doubt is that when you find something that doesn't match any previous finds there is always a lot of doubt. And there is a lot known about the Neanderthals. They are about the best studied early humans around. Well, there remains are around.
As far as travelers from Africa, that wouldn't matter, because at that time Africans were at about the same stage of development as the Neanderthals. The first remains that are considered to be those of undoubted modern humans are from around 100,000 years ago.
Bill Gill
