1. This is an outstanding system - but as Mark says its focus is infantry, and really is based on modern smokeless powder fire arms with magazines. I would say the earliest period we could model would be Spanish-American war.
Lets be honest the difference between a Moisin-Nagant and an M-16 is negligble compared to the difference between an M1 and a rifled musket.
2. Modules I would be interested in (in order of preference)
Red Dawn - US irregulars versus Soviet and Cuban troops (early 1980's)
Soviet - US 1980's hypothetical
Spanish Civil War
Occult World War II (all sorts of craziness)
Soviet Afghanistan involvement
US Invasion of Canada - late 30's hypothetical
Soviet Finnish Winter War
French involvment in Indo-China
WWII Pacific Theater
Soviet - US 1970's hypothetical
I would like to see maybe a tool that would allow you to create the counters easily so the only hard part would be to choose the background on the counters and the picture. Once you set the unit values the system would populate the "document" as needed. I'm still thinking of this one.