Production 5- Photoshop Adventure

In order to create the background that I desire, I have to use another editor since InDesign does not have the features needed to key out an image from a greenscreen; therefore, as for the dreamer's image standing in the U.S flag representing the world, I will be using Photoshop and then translating that background layer into InDesign. I thought I was not allowed to do that and was having a hard time trying to figure out what to do instead; however. I talked it out with my instructor and I am allowed to create this background layer in Photoshop due to the absence of features from InDesign.

I can't even begin to tell you how many videos I have watched on this subject, but the ones that have helped me the most have been:

I am incorporating both methods when keying the dreamers out of the picture; however, the dreamers are looking opaque and I am having difficulty getting the brightness adjusted just right but this is how is looking:

I have battled so much with the U.S. flag's star to keep it white but I can't seem to get it right, since when I select the flag only, it selects it out. I am thinking about leaving it as it is since it is going to slow down the editing process.