Are there nice (not too expensive) restaurants near the theater?

Online even they list restaurants.

Yes , many good restaurants, all kinds, Bethesda is known for this

Literally dpzens.

yes. many choices

Potbelly and Lebanese Taverna are not far. There may be some more economical options on Wisconsin, like Panera Bread and Subway

Yes there are restaurants near the theater and also this theater can be reached with Metro (the Bethesda Station)

And lots of shopping too!

Also, Cava and Sweetgreens and a few others that are reasonably priced.

Many. My favorites are Mon Ami Gabi, right next to the theater, Silver, across the street, and Jaleo, down the street. But you will find great restaurants in any direction you walk.