Yes I agree with IWAF.

The Horniman's side of the track is a big divide in SE23. There is only 1 road crossing in 2 miles and one footbridge known as The German Bridge.

You asked also about where people gain employment . I think I saw a survey of London Boroughs a couple of years ago and it said Lewisham had the biggest % of the working population travelling outside the Borough to work.
Train and Bus services are good which is a plus factor.
A large number work in The City or Docklands.
Not sure what your line of work is so cannot really advise more.

Good luck in your move,