Why train Arya for no reason other than to extended her story
Well, to be fair, she does come back as a pretty impressive ninja, which is handy for a bit of Starky retribution. I don't have any problem with that, story arc-wise. I think it would have been even better with less of the 'magic faces' stuff, but that's just me struggling with convenient magic; I like a bit of order to my fantasy science, and not many fantasy writers satisfy me there.
When I first started the books it took me a few attempts to get past the first chapters. I mean, zombies?
Really? And even when I got a foothold, realising Martin writes absolutely superb characters, I was never convinced by his magic... it's a mess all the way through the books with no obvious consistency and a bit too much "I need a plot device to do X". But I didn't care before long, because no writer's perfect and the narrative dragged me through the rough patches.
I think the TV show writers (including music writer) and actors, on the whole, have done a good job of overcoming the raw material's limitations, and I see Martin as a 'birds of paradise' magic writer now. It's hard to see how birds of paradise evolved to be so weird and spectacular and his magic system did something similar, with pockets of limited but mind boggling capability; dragons here, flammable swords there, smoke babies as required, etc, etc... none of it fits together, it's just generic fantasy Magic, which is usually what puts folk off the genre.
But the real magic is in Martin's characters and their societies. My favourite idea in the whole series may be the whole 'iron price/gold price' thing which captures the whole of Iron Island culture in one pithy phrase. And the magic of making us feel sorry for Cersei on her walk of shame, or Jaime when he loses his hand. I could forgive Martin anything!
However the biggest limitation of all, for me, was always the zombie threat from the North. It's the least interesting and yet most important plot element, but that doesn't mean the characters I love can't still be impressive while dealing with it. Just requires a large pinch of suspension of disbelief... and a lot of CGi, which always helps.
I need to eat a few carrots before Monday morning though... I'm over 50 and my rods are shot, so all this dark stuff's a bit of a strain on my TV and eyes. Maybe someone can arrange a magical full moon for us... though come to think of it, I don't remember seeing a moon, or tides. At least there's the fire trench around Winterfell to illuminate things, and some dragon pyrotechnics.
Mmm... I may be overthinking all this. But it's one way of dealing with potential pre-disappointment nerves.