[T. O'Heir]

You cannot possibly anticipate and practice for every conceivable situation in every place.
"...open space, close proximity..." Describes nearly every shopping mall parking lot confrontation. Inside, tables and chairs offer some concealment if nothing else. Chairs fly pretty well too.
"...need to train dropping stuff..." You throw stuff not drop. Give you an instant of the bad guy ducking.
Most takeout restaurants deliver or they go out of business. Mind you, if you've ever seen the kitchen of a Chinese place, you'll never eat there again.