I have a shot at the end of the first chorus of a tune but during subsequent choruses I don't want the shot. (Or maybe one more time at the end of the out chorus, but not during the solos.) Is there an easy way to do this?

You should first take a look at Edit, Settings for This Song. There are some related options there, but I don't think you can do exactly what you want with just shots (you can with Pushes).

Instead, I recommend you consider making your song one long file, assuming it won't exceed 255 measures, by Edit, Unfold / Convert to One Big Chorus. Then put your shots where you want.

If the Unfolded song would exceed 255 measures, move it to RealBand.

[Probably the better place for this question would be the BIAB forum, where it will get more attention.]