Curious as to your guys thoughts on flying the owner / operators friends with them in / not in the plane?
Totally fine so long as it's no more than a cost share, how that share is worked out is another thing entirely, I suspect they're allowed to pay for the fuel and the landing/handling fees etc but you'd need to ask Miles and ShyTorque about that.
As long as it's not out for commercial charter you can fly anyone in the plane at any time subject to the owners approval obvs.
I really recommend that you take some advice from Miles Magister though, he can keep you right on planning and how to manage any flying you do.