So biggest questions for me that have probably been asked but I want more speculation!
1. Why he heck was a portal the only way to get to Drangleic and what the heck were the fireflies and the skeletons in the beginning of the game?? Something weird going on there that don't seem to have any answers. That opening sequence has to play into the Lordran discussions.
2. Who is the fourth fire keeper and what is significance. Lady emerald?
Portal is weird because the intro also mentions that Drangleic is in a "walled off land", but it is obvious the giants came from beyond the ocean to Drangleic, and there are people from outside Drangleic, like Carhillion and Rosabeth (but Rosabeth mentions coming through the
mountains so maybe she comes from another part of the island that contains Drangleic).
My guess is that, after all the Vendrick adventures with the giants and the Xth rebirth of the curse, the rest of the world decided to seal the whole area (probably Drangleic AND the giants island) behind some magic.
Which brings us to the fourth firekeeper. She is outside Drangleic doing the good work of sending the hollows to Drangleic, to keep the curse as contained as possible. She is definitely not Emerald.
I think what happened is that Vendrick didn't want to link the first flame and thus the Firekeepers were literally out of a job. That's why Emerald was created, to keep the bonfires running artificially.
3. Maybe it's just me but I have seen constant themes and statues of mother and baby. Is my chosen undead child of Nashandra?? What is that all about?
Some people say that the painting of Nashandra that curses you shows a Nashandra in the early stages of pregnancy.
Don't think the player character is Nashandra's and Vendrick's kid, tho. It would conflict with the major theme of the series of the chosen undead to be some random dude. Don't see any obvious candidate to be such a child so I think this is a moot point.
What's the significance of the Shrine of Winter. It seem's like a pretty important place based on the looks, and happens to be the only gateway to the castle? Why did it require such huge soul power to pass through?
Well it lets you continue to Drangleic Castle without having to climb those rocks. That debris looks almost as tall as you, it'd be impossible to climb! Seriously, the Shrine of Winter should just have been where the debris is and it would have been way less silly.
SoW is really interesting. I think it represents the Lordvessel (yes, I know about Majula Mansion). It serves the same purpose, works the same way and has some serpents sculpted inside. So basically, like the old Lordvessel, it was needed to block access to the king.
More interesting are the paintings of the interior. I don't have an explanation for them, mostly cause I don't really have a good picture of them. I think one of them is Seath and the other shows the creation of the Ancient Dragon. Could be super wrong on this. It'd be a great boon if we could get our grubby hands on some high def captures of those four walls. Maybe once the PC version comes out.
Another interesting show of lore is just before Looking Glass Knight, where there is an engraving of a giant tree, and afterwards the LGK you go under some branches/roots, so I guess that is the Ash Lake or equivalent.