If we assume that grrm was really highly inspired by Philippa Gregory's book (great post btw!), do you think it increases the chances of Jaime or Tyrion being the valonquar? They are often discarded as being too obvious... Wouldn't it be funny if it was Tyrion after all and Cersei was actually right about one damn thing?
Thanks for the ask @nenko-dreams!
After re-reading Wideacre and seeing all the similarities, I'm about 90% sure the valonqar is Tyrion. Wideacre is basically Cersei's story reduced to the bare essentials, and one of those essentials is that the main character does something to make someone want revenge on them, lives in fear of that revenge, but then finally embraces it when it inevitably comes from the source she expects it to come from. That points to Tyrion being the valonqar, IMO.
Another key element from both stories is of the main character being abandoned to her fate by everyone who has ever loved her after her deceptions are revealed. In fact, Celia tells Beatrice in the penultimate chapter of Wideacre the reasons that everybody is leaving her: because she destroys the things she loves:
‘You do not manage Wideacre, Beatrice,’ she [Celia] said, and her voice was full of scorn and disdain. ‘You ruin it. You ruin everything you love. You are a wrecker. I have loved you and trusted you and I was mistaken in you. You adored Wideacre but you have destroyed every good thing about it. You loved the meadows and they are gone. You loved the woods and they are sold or uprooted. You loved the downs and your ploughs are going higher and higher. You are a wrecker and you destroy the very things you work for.’ Her eyes flickered from me to John and I knew she was also thinking of how I had tried to wreck him too, the man I loved.
After this conversation, Celia (Beatrice's friend), Harry (Beatrice's brother-lover), and John (Beatrice's husband) all abandon Beatrice in the house, where she waits for Ralph to come kill her. Jaime's arc in AFFC is partly about him realising that Cersei ruins everything she loves (including him) and he makes the decision at the end to not return to defend her during her trial. Cersei has not yet realised that Jaime has abandoned her (that will come at the beginning of Winds), but I think we are soon going to be at the point in her story where she basks in her power totally alone (especially after Tommen and Myrcella die) and just waits for the valonqar (Tyrion) to arrive. I am not 100% sure what Tyrion's motive is going to be in killing Cersei, but I think it will now happen at Casterly Rock, just as Beatrice is killed in her beloved Wideacre.
If you get the chance, you should really read Wideacre. It is a fun, hammy melodrama, but I think it really crystallises what the tragedy of Cersei's arc is: that she has numerous opportunities to avoid her fate by not being cruel and destructive, but she never takes them.
