IMHO, Demo-Sub is very risky. I don't know how it would turn out, but I'd strongly consider taking +1 food, and most likely Large/Rich HW.What is the best Race Picks to go along with:
Democracy (7) and Subterranean (6)
The homeworld modifiers are debatable...personally, I usually take the LRHW with demo, because I like to burn turns at game start doing production (build colony bases, research factories, then build 1 or 2 colony ships) before going after tech for whatever strategy I am pursuing.