I am geting ready to finish a basement bathroom. I need to relocate the shower drain as it is too close to the toilet flange. Is there anything you can tell from the picture that I need to be concerned about? The drain pipe enters the box from the right. I am planning on relocating the box 2' to the left. Does the venting appear to be OK. There is another vent pipe located to the left going up another wall not in the picture. Can I drain the sink into the vent pipe in the picture or will it need to be drained into the main pipe by the toilet flange?