Each scene is tuned specifically so there is no good way to have a "make everything react more". Some scene would blow up then others just look bad. Adding a option to manually tune the 250 scenes seems unlikely to be used.
Each scene handles it’s own aspect adjustment so there is no global aspect. One could be added however that would mean changing over 250 scenes. I’ll add it to the todo list at least
Each scene is handcrafted and can have any number of ways to compute the aspect it think it needs. One scene might not care about aspect at all. Another scene might use width/height another can use part of the projection matrix all for different parts of the scene. Like the background might not use any aspect while the foreground do to better center the object so the whole object would be visible (Like the earth scene does). In that case it looks good with 2 monitors but as you state might look too small with 3+ wide monitors.
Does you computer sleep if you are using another screensaver like the windows built in and you are playing music at the same time? The thing is that windows sleep is a tricky beast to work with and any device on your computer can prevent it. From the mouse, your music player to your network card and even then it might not work. For example my own machine refuses to sleep no matter what settings I have tried using my own or any other screensaver.