Anything wrong with this?

Is there anything wrong with this configuration? I'm going to be connecting this PVC section to an existing horizontal run in a 2x10 joist space for a second floor bathroom. The vertical pipe is just for show - it will be replaced it with a straight 9' vertical run that will connect to the main vent stack in the attic. The p-trap in the photo is for my tub/shower and the 3" street 90 is to the toilet. I don't have enough room in this space to do a 4x3 closet bend for the toilet and I don't want to cut the joists. I'm trying for a 12" rough in for the toilet. The toilet will vent at the end of the horizontal run with no other fixtures in between. The house is 40 years old and this is a remodel of an existing bathroom. The toilet was always wet vented that way.

Coming off the bathtub, I'll be using the pictured drain diverter kit to avoid the center joist and connect to the trap. I will cut a channel in the subflooring directly under the tub drain to accomodate the diverter, but at least I won't have to cut the joist. My old tub was a 30" and the new one is 32, so my drain is directly over the joist.

I think this will be a vast improvement over the previous configuration - 90T off the toilet and 90T unvented off the tub. I'm basically replacing the fixtures that were there, but hopefully improving the venting and drainage.

Actually, a "spigot" 4x3 closet bend would take LESS room than what you have there. Do you really have enough room in a 2x10 joist space for that Y-1/8 bend setup you show, and still have slope on the tub arm? IF the drain is right over the joist, HOW are you going to avoid cutting it, unless the tub is raised or you have a "thick" subfloor, because the bottom of most tubs is almost right on top of the subfloor?

I do have a thick subfloor. I cut a trench in the subfloor for the drain pipe and shaved about 1/8" off the top of the joist. I placed the tub temporarily and I have enough clearance under there for the fitting.

As for the spigot 4x3, having read your earlier posts on that topic, that was my first preference, but when I looked at them in the store they seemed too big. I may have another go at doing it that way because the 3" 90 seems like it will be clog prone and I am concerned about not enough slope on the tub drain.