How does my planned layout look

Hi everyone. First I would like to say this forum has been so much help. I have been working on a bathroom remodel for some time now. I finally got all the demo work finished. I am now at the point the plumbing needs to be relocated.
Here is the goal of the remodel. I am putting a bigger tub in place of existing tub. I will be moving the toilet and sink across to the opposite wall. I will then add a stand up shower in reclaimed closet space.
I will put up my crude drawings of the existing layout and my plan for the new layout.
Right now the sink has a 2" drain line with a 2"vent to roof. The sink line drops down and turns a 90 running directly under the interior wall. It connects to the toilet line that runs over to the main line of house. The bathtub drain connects in at the toilet/sink junction. Hope that makes sense. Maybe the drawing will help you see it.

The new plain is to run the new shower in at the spot the sink line is currently and keep the 2" vent in place. This should serve as the vent for shower and still serve the tub????? The toilet line will be extended about 3 foot to the other wall. The sink will be moved over as well. The sink line will be 2" with a vent to roof . The sink drain will run over to the toilet line and connect in with a 3x3x2 wye or combo. This should vent the sink and the new toilet location???

I should add that our house is built on a slab. The main line runs about 8 inches behind the interior wall off bath. I am getting all permits and will have it inspected. I just don't want to have do waste time doing it wrong. I want it to not only work but be done right as well. The new lines are shown in green.
Thank to anyone that looks at this.
Billy

The drawing looks good, but what really counts is HOW you install the piping. I have seen many "pretty drawings" but when the piping was installed it was a disaster which had to be completely gutted and redone.

Thanks for responding. My plan was to connect new lav line to extended toilet line using a 3x3x2 wye. Does this fitting have to be installed at 45 or simply connect together maintaining the 1/4 drop?
The shower branch I was going to connect to the old lav line using a 2x combo or wye pointing upward and connecting to the existing vent line.

I have also been debating connecting the new 2" vent to the existing 2" in attic. That way I eliminate making a new hole in the roof.

Thank you for again for taking time to check my plans out. I am one of those that builds things in my head a hundred times before I actually do it. I also like doing things right the first time. Nothing worse than taking work apart due to mistakes or miscalculations.

I had two plumbers actually look at what I was planning and suggest using an AAV under the sink instead of running a vent. They said it would save some time and work. I just didn't like that idea. I would rather take the time and run the actual vent. Needless to say I didn't trust their advice.

This is the reason I posted on here.