I think the last "there" is somewhat odd here.
It isn't, the last there is the translation of "tam". The first one is simply aprt of the "there is" English phrase .
Yes. But why the first one is not enough? If we cut a little. I think "There will be statues" is enough to be translated to "Tam budou sochy".
I agree that the last one can be added, but I think it should be optional here.
No, it is necessary. "There will be statues." means "Budou obrazy." "Paintings will exist."
Is "sculptures" correct translation?