Talked to a plumber and he wants like $500 to power auger the drains, including money to remove and replace the toilet.

Pay a title company to do a proper title search and get them to issue title insurance through a reputable company.

I believe that when you are first starting out property management should be avoided as long as you are using a reputable agent who has knowledge on rental properties.

If anyone has a reputable commercial contractor that you can refer me, I would greatly appreciate it.

I had called a few other RE Brokers , Banks and Trades people to get some leads on Builders , Lawyers , Civil engineers , Plumbers , electricians etc .

I work well with my hands and become a 5th yr apprentice in the plumbers union before 2008 hit.

Do you call and pay for the plumber, or do you hold them responsible?

You may need to call a plumber. 

You are right BP is pretty overwhelming when you first get signed up, but there is SO much good info on here it's incredible.I have several friends who are contractors (general, plumber, carpenter...) and one who actually owns a home building/ remodeling company here in the city, would these be good resources for learning about rehab costs, labor, material costs, etc?

Plumber: one of the tenants reported that from time to time over the past 4 years, the laundry tub and washing machine drain will back up with sewage and flood her side of the basement.