There's a lot of unused space in you editor (https://osu.ppy.sh/ss/13662188/0097), i highly recommend using more your available space.
You can easily fix that by choosing your placements carefully, like for example:
Instead of choosing for something like http://prntscr.com/oqbhro you can go for something more like http://prntscr.com/oqbihi
But pay attention to your distance snap. Moving a single object will require you to move all the following ones to ensure that everything is on the correct distance snap.
As an easy diff i would recommend using only linear movements, so things like 00:20:440 (7,1,2) - should be avoided. Try something like http://prntscr.com/oqbkq0
This will also help you using your editor area btw.