This one I can do. Summerhall began construction in 188 AC, and was inhabited by 209 although probably before. 

The Water Gardens began construction in 187 AC, although how long it took to be finished I’m not sure although from AFFC it seems to have taken a few years but not much longer.

In terms of general construction times, several years to several decades, depending on the complexity of construction. In these cases, Summerhall is a small and not particularly well-fortified castle, which cuts down on time, and the Water Gardens are a pleasure palace, so again you don’t need to build defenses. 

Political theater, you say? Hmm…hard to pick five total. I’ll go with five per.

AGOT – the trial at Darry, Ned sending out Ser Beric, the throne room confrontation, the execution, and “King in the North!" 

ACOK – Stannis’ public letter, the Tourney at Bitterbridge, Stannis and Renly meeting, Tyrion in the throne room (Tyrion 

ASOS – Robb holding court in Riverrun, the Red Wedding, the Purple Wedding, Tyrion’s trial. 

AFFC – Tommen and Margaery’s wedding, Cersei’s meeting with the High Sparrow, the two queen’s trials. 

ADWD – Davos in Wyman Manderly’s court, Dany in the Pit. 

TWOW – "The Bloody Hand,” by Phario Forel. 

I think Varys sees Aegon VI burn along with his hopes for a perfect prince, and finds out that he was betrayed by Illyrio, who swapped the Aegon he saved for his own son. 

I think Oberyn insisted on going to KL, and according to the timeline, Oberyn left for KL a month before Quentyn left Plankytown and when Quentyn left, Oberyn’s death was known in Sunspear for some time as it had happened well over two weeks prior. 

1. I think the original intention was that Viserys’ army would include forces from Braavos and Tyrosh, possibly the Golden Company or a khalasar. And I’m absolutely sure that Doran meant to destroy at least the Lannister part of that alliance. 

2. If Oberyn had been alive, I think he would have sent Oberyn. 

“The Blacks and the Reds, Part II” will examine the First Blackfyre Rebellion in detail from the outbreak to the aftermath of Redgrass Field.

I have a detailed theory about the arc of the war, along with a bunch of battles that are discussed here and there. Sworn Sword and Mystery Knight have quite a bit of info if you know where to look. 

Not so much red herring as false trail – I think Eddard made it a point to spread the Wylla story around a bit to help hide Jon’s parentage. He may even have taken a boat from KL to White Harbor via the Sisters specifically to blur people’s memories with his first trip. 

An interesting question. I don’t think Tywin thought much of Aegon V as king – for one thing, their political projects seem completely opposed and I think you’re right about the kids. Also, I think Tywin probably resented the way in which Aegon kept intervening in the West because of Tytos’ weakness, such that Aegon was a reminder of how far the Lannisters had fallen. 

But this leads me to wonder – who did and didn’t support Aegon V? There were clearly rebellions in the Westerlands and Stormlands, and I wouldn’t be at all surprised if the Brackens rebelled what with a Blackwood as the Queen. I could see the Reach as also a potential area for rebellion, given the marriage crisis and the Reach’s more heavy emphasis on chivalry and social caste.

I’m guessing Aegon V found a warmer reception in Dorne, both because he had both Martell and Dayne blood and because of the Dornish belief in collective social responsibility. I wonder if a young and idealistic Jon Arryn approved or disapproved?