Basement Rough-In Moving

I need to move all three drains to the locations in the picture in yellow. Here are some questions/concerns that I have. I have busted up a bunch of the floor (it was much harder than I thought it would be). I am not opposed to busting up more of the floor, but before I do so I would like to have a rough idea of what I need to do. Any advice would be needed.

1) The location of the shower drain is almost directly on top of the 4" drain line going back to my main drain stack. Can I run the drain vertically into the 4" line?

2) How would you configure the sink and toilet drains. The sink drain could move. I would like it to come up in the back wall of the bathroom so I can install the sink and vanity and run all of the plumbing within the wall.

3) There is a 1.5" vent pipe stubbed out in the ceiling about 10 feet from where the bathroom is going to be. Should I run an individual vent from each fixture (connect them above highest fixture and run the one pipe to the stubbed out vent connection)?

4) I need to install a laundry drain. The washer will be in a closet to the right of the picture. Right now my plan is to run the drain in the wall and go down into the ground about even with the location of the shower then bust up some more concrete under where the shower is going to go and run the rest of the drain and connect downstream of the last connection for the bathroom. Does this sound logical?

Thanks in advance,

Jim

No picture but as far as #1, it is very unlikely you can make a proper connection and still drain the toilet right into a pipe beneath it.

Sorry about that. Here is the picture.