If you can vent ONE bathroom exhaust then you certainly vent THREE!
DIY
The submitter wrote: "The ad listed the house with a "whole house attic fan". Professionally installed no doubt."
The submitter wrote: "Instead of flashing the penetrations, install buckets with pipes under the drips."
All is well till you start picking bugs out of your teeth Bubba.
The submitter wrote: "Screw that I-beam - just cut it. That is the framer's problem."
When you do not have an outlet box, use a Nike box. Just do it!