Is it okay to let my rats run around unsupervised if I...?

I have 2 female rescue rats, Sunshine is 1.5 years old and Hiccup is 1 year old. I let them run around my room, and I hide treats all over for them to find (Healthy treats like cheerios, pumpkin seeds, dehydrated veggies/dried fruit, oats, barley,dog food, dog biscuits, sunflower seeds, etc.) And I made them a clubhouse out of cardboard boxes that they love to play/sleep in. I have completely cleaned my room, and unplugged all electrical cords and placed them out of reach. I covered my bed in a sheet as well. The only things they can get to is their cage, and underneath the dresser/bed/table and their clubhouse. I also put tunnels/toys out for them to play with. The thing is, I can't stay in my room all the time. Is it okay to let them be in their unsupervised, with the door closed, for some periods of time? I will of course come in and check on them but do I have to be there all the time? Also, how much food should I give them? I have been giving them free choice Harlan Teklad lab blocks, and about 1/4 cup fresh fruit/veggies daily. (along with the healthy treats--about 1/8 cup or so). They don't usually finish all the fresh food, and sometimes they aren't even hungry for the treats. Should I be feeding them less?