As you have seen there are two different things the PATH to a node and the NAME of the node. To avoid confusion its best to keep the two in agreement. But as you have seen there are slightly different encoding rules for paths.
If you use the FileFolderService then this is all handled for you.
Sorry, I don't understand… I must to change the path too? The FileFolderService have a method to set the PATH of the node? I can't see a set method to do this \