If that's the case, then why even use Sansa's necklace in the first place as a means to smuggle in the poison?
I'd say the difficulty of getting shit done in Kings Landing. Spies everywhere, especially watching royalty. Tyrion makes a very clear point of this in his concern to Bron, and it's something echoed throughout the entire series with characters like Varys and Littlefinger. Nobody of significance can take a piss or fuck without
someone finding out, and even Jamie reiterates this when Tyrion suggests he have someone teach him how to fight with his left hand. Smuggling in poison I'd assume would be a pretty big fucking if: always people watching the docks, tracking shit going in and out, spies outside of the city. It might seem trivial and easy but I dunno, the point seems to be nobody in positions of interest can do anything without someone catching wind.
I also kind of took Varys reaction to the event as a "I know what's going on, but only because I'm reading the situation as it's happening, and actually a little bit surprise that the obvious is entirely new to me."
Could be wrong about that though.
I'm on the same bandwagon as you about the Tyrells, but I'm assuming the Jester guy is in it with them. Huh... I guess we'll find out for sure, but I think it's more likely that the guy has been tasked with sneaking Sansa off to High Garden.
Oh I think the Jester/Drunk is in on it. Maybe he isn't escaping Sansa for the Tyrells so much as himself. No idea.
I only see Olenna and at one point Loras, not the rest of the Tyrells. They only seem interested since she is the "last" Stark and the key to the north.
Olenna doesn't seem 100% politically motivated though. I know that's like...the thing with Game of Thrones. Everyone is. But unless Olenna has me tricked too she does seem to combine her sass, wit, and political scheming with genuine empathy. Joffrey was a colossal piece of shit and her granddaughter was marrying him, and she'd knowing know she wouldn't be safe with him no matter what. Whatever her ultimate reasons, seeing him die would potentially free her granddaughter, and she has no reason to implicate or punish Sansa, who is empathetically like what her granddaughter could end up.
Hence my conspirscy theory that Cersei did it. She couldn't control Joffrey well before the wedding, and now his new wife would have him wrapped around her finger. She offs him and can stay in power through Tommen.
See, I'd believe this because it makes sense, but I don't see Cersei as that vindictive against her own children. For all of Joffrey's awfulness to not just others but her, she's also weirdly protective and obsessive over him, even when she recognises his tremendous flaws. She also seems to subscribe quite openly to the Lannister lust for power, which while gives weight to her killing her son, conflicts with the fact she's still expected to marry Loris (maybe not now) and that her father is still going to sell her off. She knows Tywin ultimately controls the strings and she'd be better off making daddy disappear if she really wanted to start securing shit.
