re: What are those white things?
According to yesterday's press conference these may be orographic clouds so there may indeed be underlying topography . IIUC VIMS indicates their altitude to be ~15 km, which is where methane should condense. A time series shows movement and changes in the features
link
More Titan images have been sent down (along with distant shots of Iapetus, Tethys, Dione, Mimas) so they can look at a longer sequence of movement.
