Why don't you close DW at the end of the day so it can shut down properly?
I never thought of that! BUT... it shouldn't crash. No other program does! I leave a few open; photoshop, after effects, some others.
Could be caused by a backup drive or some other application running in the background. There's no way to be sure without looking at your crash logs. I keep my computer on but I always close down my apps at night to protect them from power outages.