bathroom soil and waste pipe uncertainty

[Ahearsum]

I'm creating a wet room out of a bathroom. I lifted the floors to find the soil pipe run as in the attached diagrams. Two questions (assuming I can get the required fall)

1) Is this soil pipe arrangement (in yellow) look okay to you? It looks unnecessarily convoluted to me. I think there was previously a toilet where the the end cap is.

2) Do the waste pipe runs (in red) that I intend to put in look okay? They will join the soil pipe with strap on bosses.

I think the soil pipe arrangement is asking for trouble but its been like that for years I presume without probem. I have taken the dead leg off as a start and will put an end cap in there. Doing much more will be tricky as you can see from the limited access shown in the photos.
Any thoughts?

 

[ShaunCorbs]

agree the soil doesnt look the best route but if its working

i would use a 2" pipe and combine the both eg basin and shower waste and use an anti vac trap on the basin would simplify your runs eg 11/2 straight from the shower to the basin run etc

 

[Ahearsum]

agree the soil doesnt look the best route but if its working

i would use a 2" pipe and combine the both eg basin and shower waste and use an anti vac trap on the basin would simplify your runs eg 11/2 straight from the shower to the basin run etc

Thanks. Leaving it would be the preferred option if its not too crazy.
I like the idea of combining the wastes but i went to a lot of trouble replacing the joists and I'd be gutted to notch or drill holes in them.

 

[ShaunCorbs]

Thanks. Leaving it would be the preferred option if its not too crazy.
I like the idea of combining the wastes but i went to a lot of trouble replacing the joists and I'd be gutted to notch or drill holes in them.

run them below and through the wall ?