I personally would not use the fig 9s to hang my hammock from; lack of trust and a love of webbing. But for tarps, it doesn't get sweeter. The small ones might weigh 2 grams. The ease of which I can adjust my tarp more than compensate for the extra weight burden.
There are instructions (if desperation overtakes you) on the fig 9 packaging that will show you how to use them with either one or two ropes. Read it once and you'll get it; very easy to use.