We live north of Atlanta and are looking to have ERV installed and have had about 5 people out for quotes.  With that we have had five different quotes on instal. It seems no one really knows

Our home is two stories plus a basement.  The erv would go in the foamed attic above the second floor, where the hvac is that serves the 2 nd floor.  Unfortunately we have only walls in the attic on an angle.

Question 1-my understanding for balanced ventilation that erv should pull exhaust air from the bathroom exhaust fans and should put fresh air into the rooms thru their own vents.  Some have suggested using the existing hvac vents to deliver the fresh air, that is not ideal correct?

Question 2- how to solve the hip wall problem in the attic.  Some have suggested pulling fresh air from the soffits, some have suggested going thru the roof and putting a longer pipe on to not pull in off gas from roof shingles.  which would be appropriate or is there another solution?  We just had a new roof installed and I would rather not make any holes in it.

anyone have exp with the bathroom exhaust fan ervs could we have two of those installed instead?  Would it do an adequate job?

Thank you