Like another PP, I live in the Heaton Chapel/South Reddish area and where I live there are exellent travel links with the motorway, trains, trams from Parrswood, lots of green spaces, Stockport town centre is definitely on the up with some amazing bars, restaurants, cinema, museums etc on the doorstep and I live in a little street that is so quiet that you wouldn't realise we're so close to the main route into Manchester/Stockport.
Where I live, there's also ample parking which is tough on terraced streets (I'm in a semi)
My Nanna used to live on Randolph Street in Levenshulme and the house was tiny and it was all just so "concrete" everywhere and parking was a nightmare, there was no community on the street (although obviously this may have changed now and could happen on any street) and it just wasn't a nice place for her - although she never said she felt in danger walking about, but she moved because it just wasn't a "nice place to live every day" (in her words).
My Dad also lived in Levenshulme on Leybourne Avenue and the house was much better proportioned and there was a community feel and it was only a few streets away from Randolph Street and he then moved into Gorton before moving down to Heaton Mersey (again in Stockport but with excellent links to Manchester and anywhere else due to the motorway being minutes away and there are all different styles of houses and most are excellent for being a family home if that's what you want at some point without moving again.
I guess my advice is do your research on any areas you're interested in - check the GMP crime rates, talk to locals if you can, check the streets you're interested in both in daylight and at night to see how parking gets or if there's any undesirables hanging around, check the local amenities etc.
Also remember that a "bad" street may be totally different in feel and atmosphere from the street next to it, so don't lose hope.