From an English persons perspective (tourist who has visited Wraclaw) - its got some excellent little restaurants, for me it knocked spots off Krakow (no offence to Krakow) - so you have some very tough competition. Im not one to go for the whole "lets find somewhere English to eat" but there are those that do..Im sure ex-pats would love it..nothing like a taste of home..
I think this is a good idea:
English speaking staff might be a novelty value especially if you opened near a University.
But remember English speaking might mean they're from Asia so stew and dumplings and shephards pie on the menu might not go down so well...
I think to get locals in you have to be competitive (no different to the UK these days) and have an edge of what's already there...small menu with a mix of Polish traditional and English traditional dishes....perfect!
Thats not a bad idea, you have two types in the UK - the stationary burger vans (they usually knock out great cheese burgers)
You mean cheap "barely legal burgers" that only people who've had at least 10 pints will drink?