@haitch Well regarding other passphrases can be added to the code i guess. Regarding the other questions it have to be someone with more inside knowledge about how the Smart Contracts really work since the information i have is extremelly limited xD
But ofc that lets suppose that someone that have a GPU mining farm dies and his son/wife/mother/grandmother whatever unplug this cable from the wall to those PCs, the GPU's stop generating coins and in that case its not worth having a passphrase for that account obviously, so the only real way of getting that case fully cover is if someone have a written will with instructions about how the asset closure or future may proceed and probably by pointing a respected member of the community to get things done in his absense ;)