These are a few questins already asked through e-mails. It should be organized by themes.

'''Q1''' - How can I plot the land/sea mask on the SST graph like you have on
yours - is this defined in grid_config.def ?

'''R1''' - No, all these global plotting options are set in plt_def.pro (which is next to post_it.pro).
For the continent one, you need:
   cont_fill = 1         ; continent fill for atmosphere grids (1/0)
   cont_real = 1         ; draw real continents (1)

'''Q2''' -