I think that the save functions are a bit restrictive...
I normally use the save function for a couple of variables max and I have to save the whole scene to do so. This is more taxing for the device to save and load and it takes longer than just saving a single int value. (I usually work around this by having a different layout where I save and load the game and then redirect to the menu, but this could be done much easier if saving a value would be possible...)
Also not having a way to clear save files from within the game is quite bad...
I don't know how complicated these things are to implement, but I think they would help (at least me =D) a ton...