Addition Bath Plumbing Drainage?

Hi. I'm new to this forum. I'm a DIYer in Seattle and I'm working on the plumbing for my new bathroom and washing machine closet. I currently have a 3" vent stack and I intend to install a 2" vent for the toilet and washing machine and a 1 1/2" for the sink and shower. I drew the picture below and an looking for some expert advise. Any comments are appreciated. Thanks,

What you have drawn would not pass inspection in Seattle.
The toilet is not vented,
The sink is an illegal S trap
Where the 3" ties into the 4" you need a wye fitting.

Good thing your asking ahead of time...

Are you guys under UPC in Seattle¿