The next few pictures show some of the other drains. The first picture shows the toilet and vanity drain. The only vent in this bathroom is on the vanity which is upstream of the shower and toilet.
The second picture is showing the same toilet and vanity drain from a different view with clean out.
The third pic shows the shower draining it downstream of the toilet.
Thanks for any comments and for taking the time to analyze the pictures.
Basically the entire house is 2 full baths and each bath has a 2" vent on the vanity.