Yeah it happened when Tyrion was the hand... so I think season 2
No, Bran had warged into Hodor when they were hiding in that tower, when Jon was right outside fighting with Tormund and Ygritte
I really wish we had seen a reunion there of the "normal" Bran with Jon
As for Jojen, I don't think he was slowly dying, he just was weak because he had a seizure when he had a vision
oHhh how I love that Ghost was the one to kill Rast!!!
And Ghost and Jon reuniting!!! So adorable!! We definitely ship Jon/Ghost