I had this EXACT worry when Puppy was younger. Could not be trusted in open spaces, crated for MANY hours a day when I work and sleep.
Some things that helped me:
1. Even when not crated, if left alone in a room, she is usually sleeping. This helped me feel less guilty about crating her.
2. Try exercising her BEFORE you go to work in the morning so she is more tired and may sleep longer in her crate
3. In regards to constant activity, after exercising her, you can maybe tether her to you with a waist leash. This will let you do something else and be LESS exhausting.