Fernando,
as land pattern I've used the same value used in the EVK: 12mil. But I suspect that 13mil will be also appropiate.
With 4mil width/space for tracks and 8mil/16mil pad/hole for vias: the minimum reliable track/space for mask has been 0.08mm, in my case. DON'T FORGET TO COMPLETELY TENT ALL THE VIAS UNDER THE BGA COMPONENTS. Regarding to the solder mask: I didn't put anything and my assembler did it for me.
My custom board works right. On any case I've planned to buy some IPC standards in order to be sure of what I'm doing on next designs.
Hope be helpful.
Manu.