For all the questions asked, I suggest that u try to re-read some of the manga pages and watch alot of the anime especially the fillers
For question 1; Sasuke Stabbed Karin when he killed Danzo by stabbing through Karin's chest to hit Danzo's heart with the Chidori Spear whilst looking at his internal organs with his Sharingan... you can watch the anime on youtube just type Sasuke Vs Danzo
For question 2; Karin had a Picture portrait where she had a picture of her and Sasuke and then she started cursing sasuke and pretending she was mad, but as the guard walked away, she used her glasses end to open the portrait and there was a lock picker hidden behind it.
Fro question 3; Most of them are in a high building where they are being guarded. This was shown in one of the fillers in the anime
4. Kagami Uchiha has been mentioned before, in the anime when Tobirama and the squad of leaf villagers were being pursued by the guys from Kumogakure's that contained Kinkaku and Ginkaku (the Gold and Silver brothers), Tobirama and his squad discussed their options, and Kagami said that ambush wouldn't work because the Kumogakure squad is too large and that instead a diversion was needed to save the rest, Danzo was scared of saying he will be the sacrifice for diversion but Hiruzen said it but Tobirama decided to make Hiruzen the new Hokage and went in for the diversion and got killed (therefore in a funny twist, he took an advice from an Uchiha and died)... Kagami was even mention during several debates that we had on NB about who Tobi was, some said it was Kagami because no one knew about his life after Tobirama's death.
5. FTG is Tobirama's original technique if you go back and read where or before Minato fought Tobi... Also, if you read other translations of where Tobirama cut Izuna, it was stated clearly to be Flying Thunder God Sword Slash. Therefore that should hint that he had it and even when you read his bio on Naruto wiki, you will see it.
6. Sasuke appears to be good now, however Kishi can change it at any time... I believe Orochimaru is still evil simply because a snake is always a snake in Japanese myth and he is just following Sasuke until he gets the opportunity to steal the body that he so dearly wants and he has gone further to achieve his first step of getting the rennigan when he gets Sasuke's body; by first acquiring Zetsu's body which is made of Hashirama's cells. However, this is the point where we will see Naruto Vs. Sasuke part 2, where Naruto will save him and beat Orochimaru out.
