I don't think that neither of these are possible with the open-source gdal2tiles or maptiler - simply because the way how the utility has been originally designed.
Antialias was just a dirty and fast hack how to merge mutliple files.
A proper implementation is done in the C/C++ reimplementation of the MapTiler, where both of the requests you have are possible simply by specifying multiple input files and relevant output parameters (gearth profile and hybrid format). This version of MapTiler is available commercially - please contact us for a free demo (
http://www.maptiler.com/). You will also get very good optimization of the output directly, faster speed and several new features.
Petr