Hi there, I spent a few hrs today roughing in my drain and water lines.

Two concerns:

1) Does it make a difference that I'm coming in from the ceiling, and my stub outs come from the top down, when it comes time to install air chambers, since in essence, they will be upside down?

2), my vent rises straight into a ceiling rafter :mad: :mad: I didn't even look up to see it... should I just elbow around the rafter, or extend my drain over more the left with a coupling and have it a bit off center under the vanity? You can see in the pictures:

Other than that, will this install pass code? The garage will eventually be finished, and all those pipes will get buried in the wall. (don't mind all those wires, I actually know what I'm doing with those ;) Thanks!

What are you plumbing in, a laundry sink?

The fittings covered up by the towel, is that a medium sweep 90 with a sanitary tee stacked on top of it? If it is, it should be a long sweep 90.

Medium sweep 90's are fine going from horizontal to vertical, but going from vertical to horizontal requires a long sweep 90.

As for the shock arrestors, which I am assuming are for a clotheswasher, they can be installed in any orientation you like, but they must be made accessible.

BTW, shock arrestors are required only for solenoid actuated devices -- Clotheswashers, icemakers or dishwashers being the most common three.

As for the vent piping, if this rough in is for a single sink, then you can use an air admittance valve and bypass the need to tie it into an existing vent.

It is a bathroom group, just the tub is not pictured... I was under the impression that the shock arrestors were needed at the lavatory and shower faucets as well? I see what you mean about the long sweep 90 and will change that out. Thanks.

1) Does it make a difference that I'm coming in from the ceiling, and my stub outs come from the top down, when it comes time to install air chambers, since in essence, they will be upside down?

We call them drops instead of raisers and your air chambers will be right side up coming off a upright tee inside the wall. We place air chambers on all lavatories and the kitchen sink. Shower air chambers are not needed.

2), my vent rises straight into a ceiling rafter I didn't even look up to see it... should I just elbow around the rafter, or extend my drain over more the left with a coupling and have it a bit off center under the vanity? You can see in the pictures:

I agree with Growler about changing out the lavatory drainage elbo for a long sweep or two 45's. You may use tight radius vent ells on your vent if you wish as long as it stays a dry vent and in a dry vent you may use as many turns as you wish.
Just remember that you must slope back to the drain. When you stub out for the vanity supplies install upright tees on the stubouts in the wall with a 12" piece of pipe with a permanent hard cap on it for your air chambers. Back and pipe strap them.
When you stub out for the drainage bring the stubout out of the wall a little off center so the trap will have a little room to swing before connecting.
Since you have already run the vent up for the bathroom group I would continue on through the roof or revent back to a existing vent in the attic.

"Other than that, will this install pass code?" Looks good to me if the underground drainage is code compliant.

Good luck, Tom