If "reduce the amount of white space around the layers" in Layout View is the issue, then you may set the size to exactly match the extent of a layer. This is how you do (unfortunately you may only do it using the extent of a feature layer, not a raster):
1. R-click the Data Frame => Properties.
2. In the Data Frame Properties dialog, choose the Data Frame tab.
3. In the Extent section, click the radio button Fixed Extent => Advanced... button.
4. In the Data Frame - Fixed Extent dialog, click the radio button Outline Of Features => choose feature layer from the Layer drop-down list => OK => Apply/OK
Now the extent of the data frame has aligned to the extent of the chosen feature layer (i. e. all white space around the feature layer is removed). You may resize your data frame (scale changes accordingly), however, the white spaces won´t return.
Hope this solves your problem,
Oryxgazella