Karlovy Vary is beautiful. There are many Russian speakers. I recommend it for a visit. You can just walk along the streets. To sit in a cafe. Go to the Becherovka museum, etc..
Indeed, this theater is an ornament of the city. It is beautiful both inside and out. It is small in size. But you can always buy tickets. Or at the box office of the theater itself (to the left of the main entrance), or by phone, or on the Internet. The troupes are usually newcomers. His own playing is not enough, there is not enough funding. Karlovy Vary's own symphony orchestra also performs.
In the same theater, local large organizations rent the entire building for their own events. The poster is always printed in three languages (German, Russian and Czech) and hangs on the theater itself. You can also view the poster on the Internet. I would like to add a small detail. Pay attention to the seat numbers in the theater, to the nameplates of the floors and rooms. All of them are made of porcelain, at a local factory! And this is not surprising, because the Czech Republic is proud of its porcelain.