After finding some time to devote to this, I managed somehow to have Mount2SD successfully mount the mmcblk1p2 ext3 partition.

Mount2SD created a boot script. Based on your input here, that is I underastand what mounts the partition upon boot.

Now, how do I tell Android to install Apps there? I don't want to move the ones already installed, nor to create symbolic links, but simply that, since now on, new apps are installed in mmcblk1p2 .

Is this possible at all?