Take a look at these threads:
http://forum.shrapnelgames.com/showthread.php?t=33786
http://forum.shrapnelgames.com/showt...ghlight=miasma
The first is a guide on EA C'tis. (you can also find it through the strategy index) While there are obviously some differences between EA and MA they are quite similar, and a lot of the points in this thread apply to MA too.
The second started out as a thread about the effects of the miasma, but in the second half you can find a little more general discussion about the nation.