Find out what about Walda Frey? Last time we saw him was his smirking over the carnage at the Red Wedding.
Walda -- the Frey married to Roose that Ramsay murdered. Not Walter.
He has got to know that will never happen, anymore than Tywin Lannister could legitimately claim the throne, even though he ran it from behind the scenes. Baelish has no legitimate claim to the throne, unless he thinks he can subjugate the 7 kingdoms himself and claim himself king - which is not out of the realm of thinking in terms of his plans. He did set this whole thing in motion by getting Lysa to poison her husband's wine and then write a letter to Caitlyn Stark that blamed the Lannisters for it - thus setting the stage for the war he wanted between the Starks and the Lannisters. Chaos as you recalled him telling Varys, is a ladder.
Well...are there really any legitimate claimants in Westeros period? As I recall from the books, if there is no legitimate heir, then the Great Lords are free to choose a new King. Didn't Ned even propose that at some point? I think they could choose whomever they'd want. LF's plan may be to arrange things so that no member of any Great House will be acceptable to the rest, so he'd be a logical compromise choice. Nobody is going to want a Lannister in charge, Edmure is goofy, Robert is sickly, and Sansa may be disqualified because she's a girl/and/or doesn't want to leave the North. Dorne is out of it, there's no Baratheons, so....who? Maybe Mace Tyrell, but they're also tainted somewhat by their support of the Lannisters, and Mace is a doofus.
But if you have a crown that is massively in debt, and a very smart guy who is a wizard with money and has been on the Small Council...I think he may see himself as a plausible compromise candidate. The guy who can "hold things together" without alienating other Houses and who can get the Crown out of debt isn't a bad choice. And he is now technically the Lord of Harrenhal as well -- which is a major title that might make him a more acceptable contender. Otherwise...where is his ladder going? Being on the Small Council wasn't enough for him, and being Lord of Harrenhal isn't enough. So if he's still scheming, what is left for him other than the Crown? Sure, it's a tough play, but I think it's the only thing that makes sense as his ultimate goal.
Doubtful. Sansa lied for him upon questioning by the Lords of the Vale. She would be held complicit in his treason if she admitted that.
Given the circumstances -- "he told me I was wanted for the death of Joffrey and that you'd turn me over to Cersei Lannister" -- her being merely a witness isn't something I think they'd hold against her. After all, all the Lords of the Vale were manipulated by him to some extent, and so I think they'd have some pity on a teenage girl who had her family murdered, and who did eventually tell them the truth. She didn't kill Lysa herself -- she just covered for LF because she was terrified.
After all, what would they do to her if she told them? She's still Sansa Stark, and I doubt they'd try to punish her and go to war with the Starks. In any case, she'd certainly get off more lightly than LF would, so if she had the cojones to rat him out, he'd be sunk. I do think you're right in that "she wouldn't dare tell" is what LF is telling himself, but I also think he knows it isn't a certainty.
Oh I don't know. Tyrion's discussion about 'conversations in elegant rooms' was pretty good prose IMO.
That was pretty good.
That I do not know. I'm still trying to figure out why they decided to back Ramsay at all in the first place.
It makes sense for the Karstarks - they're complicit in the murder of Robb and other Northern Lords, so they're kind of stuck with the Boltons. The Umber explanation was that Jon was a traitor who let the wildings in, so they need help to defeat the wildings and put in a better Lord Commander. Just not sure I buy it.