If you want to open a shop you might want to consider what works well in East Dulwich (your previous home according to previous posts). I would suggest that the butchers, fishmongers, bakery and delis work well in attracting people to the town centre beyond our fine Sainsbury's.

I don't think I've ever been into Bunka, but Mayo Maker, Oliver London, and Tilt have not exactly thrived in Forest Hill. I'm not sure that people see Forest Hill as having enough variety for clothes shopping and they are probably more likely to go to Lewisham, Bromley, Bluewater, Westfield, or West End. It would be lovely to develop a centre for independent quality clothes retailers, but I suspect it is a difficult market and requires a few shops to form a core group and attract people from a little further afield than the current high street does.