Shacko
Master Plumber-Gas Fitter
Ok update, I hope this works, I redid my plan and I'm kinda into the point of no return, so here is what I have.
the floor drain and shower both have traps of course, the vent on the shower is a 2x2x1-1/2 san-tee, you can't see it very well in the pic.
Unless you are required to have back-water valves you are creating a future PITA, they also need a service port at grade level. I don't know about 1 1/2 underground, most codes forbid it, if you read my other reply I addressed the problem with the floor drain.