the Other Wolf

In order to take on the persona and live out her days (or the war to come) as the Hound, NO. Is there a chance she pulls a "Ghost of Renly" move, maybe yes.

Maybe a link or two. Then when Oldtown is sacked, Sam saves some old books from the library and returns to the wall with them.

YES!

Welcome to the forum! A very similar thread was just started. Enjoy.

No. Yes, but Lysa does not know that. I would phrase it differently, it was not his "dying brain", he consciously knew he was dying and was trying to get the information out.

As far as I have observed, GRRM does not tell. The answer to your question would probably spoil his story before he is ready to give it away. With that said, this is a question that is leaps and bounds better than most that are asked on this forum.

I lean towards not Bloodraven.

Ramsey could have used the seal and then someone else opened the letter and resealed the letter by smearing it with the same wax.

NO

This

Interesting, but...

Does anyone think they know who the man in the cave is?

Its not just night vision, but being able to see below deck.

Uhhhhh.... NO

I think I have read a thread or two on this topic. Everytime I have a question I ask God, er I mean, Google; ASOIAF XXXXXXXXXX. XXXXXX=question You will end up here. Welcome to the forum.