As to plumber, I loooove my plumber: Toby Jones 770-572-0307. Originally found him on craigslist, but he's fantastic and inexpensive and reliable and he does all my houses.
I think neighborhood categorization can so differ between perspectives.
I moved into Grant Park in '91 and everyone that heard about it, but hadn't been there in a long time was asking whether I wasn't scared and whether I had a gun. The first night I spent in my new old house I woke up with loud gunshots. I was terrified. It was right behind my house and sounded as if a gang war was going on. I got dressed, grabbed my cat and my purse in order to drive to a hotel somewhere. As I came out my front door, I noticed all these people on the street, watching the fireworks from the stadium a few blocks behind my house, because the Braves had just won a game.
Some people thought it was a D neighborhood, I never saw it that way. I proceeded to renovate about a 10 Victorians in the following 15 years in the area. Never had the need to carry a gun. I always loved the neighborhood.
From Grant Park I moved into Adair Park in 2003. I saw the same housing stock, so close to Downtown and saw a neighborhood that was so due to shine. Unfortunately, mortgage scammers took on everything in 30310 and destroyed so many properties. And I did some research and turned a few larger ones over to the FBI - hehe.
Adair Park houses are in the +100K range , very different from West End. But West End has pockets that are gorgeous Victorians and there are pockets with rundown crackhouses, so, I think it varies a lot.
Right across from Adair Park, on the other side of Metropolitan, there's Pittsburgh. Most investors think this is a total war zone. But I started buying there in 2008, because I knew the neighborhood well (had been flipping lots there a few years before, when I lived in Adair Park) and knew that it really wasn't so bad. I got great deals and don't regret buying. I can live of the income now. And I lived in 1 of my houses for 1.5 years in 2011/12 , white, blonde, blue eyed with a red convertible. Never had anything happen to me. I walked all through the neighborhood daily, between my houses. Yes, there was a certain amount of racism against me by some, but I was never attacked or had anything happen to me. Most people are just hardworking people, who try to make ends meet.
So, I think the best thing to get to know a neighborhood is to farm it. Not to work on 10 areas at the same time and be a jack-of-all-trades, but become a specialist in whatever neighborhood you want to work in. Walk it. Talk to people. Get to know the neighborhood. Introduce yourself. Give out your card with promise of reward for turning you on to a house. And make up your own mind. Perceptions may still be from some years before and the areas may have changed since.
Just my opinion ;-)