I love the books, thanks for writing them, yadda yadda yadda [end perfunctory thank-you section :-) ]
Thanks for reading them, yadda yadda yadda [end perfunctory you're-welcome section]
Are all the Stark children wargs/skin changers with their wolves?
To a greater or lesser degree, yes, but the amount of control varies widely.
Yes I know that Lady is dead, but assuming they were all alive and all the children as well, would all the wolves have bonded to the kids as Bran and Summer did?
Bran and Summer are somewhat of a special case.
Did the queen of thorns really poison Joffrey?
Littlefinger says so. Would he lie? <g>
What was the poison?
The strangler.
I think the broken horn that Ghost found with all the obsidian is the real horn of winter. It hasn't been mentioned yet though. Any comments?
Nope. Keep reading.
Also, I believe that Coldhands is Benjen Stark. Can you confirm this?
See previous answer.
Second to last question. More of a comment really...I don't think you should have made a 5 year time lapse between ASOS and ADWD. There are many plotlines that you didn't resolve at the end of ASOS. It's not fair to resolve them "offscreen".
Nothing important will resolve offscreen.
Last comment (I swear! :). Oberyn the Red Viper should NOT have died. In him you had one of the coolest and most interesting off all your characters.
Wait till you meet his daughters.
There's no way that Clegane would have had the energy or strength to kill him.
That's what Oberyn thought too. Famous last words...