I find isometric drawing much easier to read, and highly recommended anytime you are drawing plumbing.
From what I am seeing in your drawing, the water closet waste is passing the shower drain connection, and the shower is not vented.
If you simply bring the shower drain under the wet wall, the vent can come up into the wall, putting the drain connection to the 3" line between the lav riser and the basin.
I cannot tell what your intentions are for the water closet. The vent cannot be anything but vertical until it is at least 42" above the floor, and you should not use a sanitary tee on it's side or back. A wye is the proper fitting for a vent take-off.
Edit- Same with the lavatory drain. The below-grade connection to the horizontal drain must be made with a wye.