First time guy with plumbing and slab ?

Hello everyone. I currently am combining two bedrooms into one and taking the 1/2 bath in the master and making it a full bath with walk in shower. The big issue is this is a slab ranch house. So demo of the slab is necessary. I have attached a print of the project. My question is how I plan on routing the drains for new shower and vanity. Please advise if its all messed up or changes to make things better to plumb...thanks again.

View attachment drains vents.pdf

 

I live in Ohio if that matters. Basically the plan is to expose the toilet waste line and cut the cast pipe out, tie in a PVC with fernco and t- off that to pickup the shower drain. The sink drain will be picked up by the shower line with a wet vent.

 

I live in mass in a town that has a lot of slabs there was a domestic water
leak in the slab in the kitchen..there were pipes and
conduit everywhere no rhym reason.i also worked in another house
changed the tub out to a 3 peice the drain was broken off just before the trap
(Style I have never seen) it was 16-18" below the floor
thre were 3/8 lines buried in the slab it was a nightmare
all the toilet flanges were broken it allgog fixed is the heat still in the floor???
check you water piping usually nice and green Change what
ever you can with the floor open sometimes the heat was
run in the attic and dropped down in the walls if its up there
make sure it's well insulated or boxed in heard of lots of
splits because this good luck