Correct (but you're using the word immortality like most people do, and not like the Society does). But being perfect, you won't ever make a silly mistake like walking off a cliff ;-)
And presumably God would also have to protect people from random occurrences. As I pointed out in another thread, if you enjoy nature walks in the new system, you're almost guaranteed to be killed by a falling tree branch some day, statistically speaking. Perhaps it will take a million walks through the forest, but it's bound to happen eventually. We won't even touch on subjects like going into space and getting hit by a space rock that no one could have seen coming. God will just have to have angels everywhere watching out for stuff like that.