The pipes are indeed low on that side because the soil pipe goes under the exterior wall’s skirting. The horizontal pipe under the toilet will end up being buried.
As for the AAV here is why I’m kind of stuck with that. I hired a plumber to cut the cast iron vent stack so I could tie into it without disturbing the section that goes through the roof. He said there was no way to secure the straight pipe in the attic, so he cut it in the wall under the bell/hub so there would be a way to clamp it and hold it up. Made sense at the time, but now that leaves me with no way to tie the vent on the opposite wall to the CI pipe in the attic. I am hoping the AAV is sufficient, but if you all say it’s not, I will need to take out the section of CI that extends through the roof so I can connect the two together.
Overall I tried to hit all of the points I have seen you all address in other threads, and what I understand the code to read but I am still questioning my understanding of them, so please tell me if I got any of it wrong.
#1 the dry vent stack comes in after the first fixture so the entire horizontal line is wet?
#2 The lavatory can connect to the toilet drain? This one Im a little fuzzy on especially on what fitting to use, so I would appreciate advice on that connection. Can it be done, and if so did I use the correct fitting?
#3 I’ve seen many posts saying the toilet is always last, but florida code says for horizontal wet vents any fixture not part of the bathroom group must go downstream of the group. (section of code attached). I may be misreading that so again appreciate your feedback.
Thanks for your time helping me with this.