I am not entirley sure about this, but can't you just use the newly added debugger functionality to see how much memory/CPU power the game is consuming and just look at the file size on the exported/built app to see what the download size will be like?
Of course, if you'd like this sort of feedback in real time while running the app without using the debugger, i'm sure that you could just create a text object on a static layer (always in the same position on screen) and update the text how often you desire...
Something like:
Every 0.1 seconds -> Set text to
"Renderer: " & renderer & " FPS: " & fps & " Image memory: " & ImageMemoryUsage & " CPU use: " & cpuutilisation & " Objects: " & objectcount
Which would show you the renderer being used (WebGL/canvas), the current frames per second, the memory used for images (works in WebGL only, apparently), the current CPU usage and the amount of objects...
As for viewing the data in the editor, however, i am not sure...