How does my rough-in look for a custom bathroom and kitchen wall?

The biggest red flag on a wall like that is usally what happened to the framing. If you bored thru the **king studs or jack studs** to get those horizontal drain lines or vents through, you’ve likely compromised the structural integrity of the opening. Most inspectors will fail that on sight becuase those studs are carrying the header load. You usually want to use a different layout or a header design that allows for the plumbing to pass without drilling through the support members of a door or window opening.

Regarding the vents, check your height. If your horizontal vent pipe is sitting below 42 inches—or less than 6 inches above the flood level rim of the fixture—you’re asking for a correction. It needs to be high enough that a backup in the drain doesn't send waste into the dry vent line. Also, make sure you used a **double fixture tee** if you’re piped back-to-back. A standard double sanitary tee is a no-go in most jurisdictions because the waste from one side can shoot straight across into the other trap.

Your P-trap height for the kitchen needs to account for a deep sink and a garbage disposal if the homeowner is planning on one. If the rough-in is too high, you’ll be cutting into the wall again once the cabinets are in because the disposal outlet will be lower than your drain. 12 to 15 inches off the finished floor is usually the sweet spot for kitchen drains to keep things flexible. And don't forget the **nail plates**. If you've got PEX and ABS tucked into those studs, the drywallers will absolutely hit them with a screw if you don't have heavy-gauge plates covering every single penetration. Even if you think there's enough clearance, it's cheap insurance. It sounds like you've put in the work, but double-checking the boring and notching limits in your local code book before the inspector shows up is your best bet.

I'm still trying to wrap my head around the difference between a double fixture tee and a sanitary one. Does the fixture tee just have a longer sweep to prevent that crossover issue? Also, with that mix of PEX and copper, what's the safest way to join them if it's getting covered by drywall? I've seen those push-to-connect fittings everywhere but I'm nervous about using them where I can't see them. whould you guys suggest a crimp adapter or somethig else?

Stay away from those push-to-connects behind a wall. They’re handy for temporary fixes, but for a rough-in, use a brass sweat-to-crimp adapter. Just remember to sweat the copper side before you crimp the PEX so you don't melt the tubing. Also, make sure those stub-outs are rock solid. If you’re just poking PEX thru the studs, use drop-ear elbows or a bracket like a HoldRite. It prevents that "wet noodle" feel when someone turns a valve and keeps things from rattling. Have you run a pressure test on the lines yet? Better to find a small weep now than after the tile is set.

Don't forget to put a gauge on those lines and do a full pressure test before the drywall crew shows up. I’ve seen way too many guys skip the air test on the ABS and then find a pinhole leak once the water’s running. Also, on those electrical runs you mentioned, keep the Romex away from the hot supply lines. If they’re touching, the expansion and contraction of the pipe can eventually rub trough the wire jacket or just cause annoying clicking sounds in the wall every time someone takes a shower.