So my mage buddy cast Orgasm at force 5, which worked out to 0 drain. So, as far as I can tell, each point of force adds to the net hits he gets? But that seems like a lot of power. So what does force do for an illusion?

Force does not add to net hits. Combat spells and Area of Effect Range are the only time Force means anything other than just being a limiter on how many hits you can have.

Combat spells - Force = Base DV

Illusion + Manipulation spells - Force = the max amount of hits you can have for your spell. This is important because the amount of hits you have is the TN for people trying to resist your spell.

Area of Effect - Its usually based off [Force in meters * Net hits = Area covered].

Some spells, like Levitate, use the AoE formula to determine effects too.

Yeah, I was only confused about illusion spells, really, but thanks. Like a lot. This site owns face, by the way. It's basically the most helpful site ever, after Wikipedia, I guess.