A useful site for Atlanta traffic information:
Georgia Navigator :: Home
I would rule out Roswell...it's further than the others. Decatur or Tucker would be your best bets for a more pleasant commute.
Crime is generally not a major issue in the overall areas you mentioned, but those suburbs cover an expansive area with dozens of different neighborhoods. The level of crime won't be consistent throughout Decatur, Stone Mountain, or Norcross...some areas will be safer, some will be less safe.
When I was renting, I never found it an easy task to locate a house to rent that was in decent shape. I rented a couple of different condos, but both times the owners ended up wanting to sell after I lived there for a year - so I had to move out. That's one big drawback, IMO, of renting a house or condo. You don't have that same worry with an apartment...plus you have on-site maintenance in an apartment community.