I have a slight preference for clipless pedals and cycling shoes for my 6 mile commute but that preference gets stronger as the distance I'm riding gets longer. That preference can also be tempered by inconvenience.

For the last few years I've been riding a fixie with "campus" pedals. These pedals are platform on one side and clipless on the other. They are ideal for me during the fair weather months. If I happen to forget to put my cycling shoes on when I walk outside in the morning on my way to work, I'll just ride in my sneakers. If I were riding 20 miles, I'd go back in and get my cycling shoes.

In your case, since you said you're getting on and off the bike constantly, clipless pedals and cycling shoes may not be worth the hassle. Some types of cycling shoes aren't bad to walk around in though, - they tend to be SPD type.