@Uchiha Macho
Not possible at all. Susano'o is directly linked to users chakra. This was clearly shown when Madara was pulled out of Susano'o or when Itachi's Susano'o fluctuated by climbing up and down different states when he himself was in pain and losing Chakra. Similarly, when Madara was pulled out of Susano'o his disappeared not long after, which means Susano'o cannot be maintained without the user.
That Sasuke having Itachi's abilities is purely hypothetical and largely a metaphorical point when Sasuke has displayed ZERO abilities of Itachi's Susano'o or his eyes other than Amaterasu, which is something that is present in Uchihas with MS. This is clear from Zetsu's statement as well, that one eye holds the most powerful mental attack and other the physical.
Anyhow, this would be dragging this on far too long, but other than fusion of two MSs to create a single EMS, Itachi's eyes shouldn't serve any more purpose and to use his abilities is far fetched in my opinion. This is one of your theories that I don't agree with, I'm afraid.