This may come off as totally rude, and I apologize in advance, but I see no difference in your style from page 1 to page 3. 
Maybe it's because the harsh shadows are covering it up, but really I see nothing discernibly different. Just like someone else said, there's harsher lighting, and that's really not a style change. Even the way you painted the shadows are the same.
And frankly, you're not going to see a real shift until you've done tens or hundreds of pages.
As for these:
... What about it is dangerous?
But also, there's really no "normal". Artists shift and change as they gain different influences or direct themselves in different ways, and there's no right or wrong answer here.
I think this is a matter of preference. Overall, it's cool to always see people improving and experimenting, which inherently comes with some inconsistency. But there are a lot of really successful artists that have nurtured a way of communicating in their art and they build a living off of drawing very consistently because it's what they're known for. Neither is bad, it's more about your priorities as an artist.
I'm honestly not sure how to answer these. I think you're digging a little too deep into the philosophy or what the shift "means" rather than just exploring it organically. Try not to overthink it so much!