Showing multiple transparent layers over base object

You have two problems; The layers have a filled background, which hides the other layers and the base, and the base (in a separate manner) is hidden to the layers. 

There is an easy solution to the filled background on the layers - you go to the master and change it. I tried that, and couldn't find the master you are using. The first master says it is being used by three slides, (even though there is only one slide) but none of the layouts say they are being used. I think that may be a left-over artifact from taking this slide out of the project. If it isn't, you have a huge corruption problem. Assuming that those things are all right in your original, you can change the background by going to the Feedback Master (push f5), select the Background Styles drop down and choose Format background. Set it to No fill, and apply to all. That should change all the layers that use that layout. (Sometimes changing the Master doesn't change layers that are already created. In that case, you right-click on each layer, apply a different layout to it, then re-apply the layout you want.)

The problem with the base not showing is easier to fix.

Open any layer, and in the lower right corner, click the visibility icon of the base layer to make base objects visible. They will then be visible to all the layers.

I hope to goodness you need all those masters, because there are so many of them that making any change is very slow. In the past, I have seen projects crash under the weight of a lot of masters.