Thanks, I think I will try to stay away from the goofy stuff! A washing machine drains above the W/C, and a shower drains above that with a vent coming out the top of the stack.
I figured a different way to route the drain from the W/C & Lavatory, though I will need to make the soffit a little longer than the one that is there now. Everything get a lot more straight forward if I just drill though the floor joists, but I'm just a little nervous about doing that if I can find another way.