Plasticity and the Play World

I'm working on a play. After putting a few pages together and figuring out most of the characters and a few of the major scenes, I'm puzzling out the rules that will govern the world of the play.

This particular play is an adaptation of Oedipus at Colonus, and I have been thinking about it for a number of years. While the original material is a tragedy by Sophocles, my version will be a comedy. It will take place in a small pizza parlor, with a counter and one or tow tables. Through the story several Greek myths will unwind. It will be like a crossroads of stories that pass thru the tale o a refugee and his daughter living under a curse. 

I am working to determine how the world will move. Will it all be in the confines of the pizza parlor, or will some of it take place outside? If it does move location, how will it be presented? These are some of the aspects of play-world plasticity that I am thinking thru. Besides being a playwright, I am also a designer. In order to compose a theatrical play, it's important that I think thru how the play breaks in my outlining and planning of the scenes. Part of this will help me understand what kind of rhythms to make from the scenes. 

For example, if the play only has one outside scene, the question is why? Should there be other scene movements? Or might it be better to establish a rule that it all takes place inside the parlor? These  are the kinds of things I am working thru.