If the governing code in your area allows wet venting then you're close....
If you lay the 3X2 wye to the shower on its side so its coming off at the same horizontal plane as your main then it doesnt need a vent. The lav vent will serve as a wet vent for the entire bathroom group. If your water closet is directly above your main then you're fine. If you need to run over some to catch it, turn the wye on its side too then 90 up to it. (hope that makes sense, but it sound kind of confusing now that I read it). The end of run clean out is not a bad idea at all.
You can tie your vent into any existing vent that eventually goes through the roof whether it be cast iron or ABS.
Again, hope this makes sense. Writing this at 7am after a long night of "fun" lol
If you lay the 3X2 wye to the shower on its side so its coming off at the same horizontal plane as your main then it doesnt need a vent. The lav vent will serve as a wet vent for the entire bathroom group. If your water closet is directly above your main then you're fine. If you need to run over some to catch it, turn the wye on its side too then 90 up to it. (hope that makes sense, but it sound kind of confusing now that I read it). The end of run clean out is not a bad idea at all.
You can tie your vent into any existing vent that eventually goes through the roof whether it be cast iron or ABS.
Again, hope this makes sense. Writing this at 7am after a long night of "fun" lol