I've got a 2014 XC70 which I've been playing with the idea of doing something similar to what you've done so I was very happy when I stumbled across your thread. I'm curious to know how you decided to go for the 30mm lift kit? I have no experience with lift kits but I have some with lowering kits where the change in angle of the drive shafts sometimes can cause increased wear on the diff. Was this at all something you took into consideration before you decided to go with the Terra4x4?
Also, how did you manage to get the wires for the roof lights through the roof without too much risk of water leaks?