I'm not figuring out how to place 3 pictures on one line in RSD.
I'm stuck here . . . (see image)

The other thing I cannot figure out how to do is place text on top of the green picture in this image.

Can anyone offer any advice?

Select the container in which you have added the images and apply the settings in the attached image. If you don't want the images centered, play with the setting for Justify to get it the way you want. Also, you can give the images a margin if you like.

Oh, I read the rest of your post. If you put the green image as a background image, you can add text on top of it.