[Gryphin]

Reguarding the -50% GC.
Using 3000 Starting Points
Yes you will need 3 times the number of troops to capturer, (or protect a planet). The 800 points I get for going with -50% Ground Combat Gave me 28% in Happyness. Since Happyness affects your empire every turn and since it impacts Reasearch and Mining, I suspect I will be able to afford the exctra troops required. Since I get a 10 percent bonus to reasearch from the happyness level, I will be able to reasearch stronger troops.
I have not played this out. It looks like it would will be a good trade off as long as I deal with the logistics properly.