I can't speak for you guys in hilly country, but here in Hollands it's common to have only one brake (coaster). I'm riding ss with only a front brake and it's harder/better/more precise than any coaster I've ever had. Those weren't really bikes you'd get a lot of speed on though, but I still think only a front brake is doable.
(Although never tried,) I think riding brakeless, with or without footretention, is BS.
Its more important for fixed riding, and its not so much the ability to stop, as the ability to avoid getting your legs/feet battered by spinning cranks, should you slip.
Its more important for fixed riding, and its not so much the ability to stop, as the ability to avoid getting your legs/feet battered by spinning cranks, should you slip.