This is what I got from your post: you want to avoid hiring a property manager and self-manage a freshly-purchased turnkey duplex. Since the duplex is new you think that there aren't going to be problems managing your duplex.
No matter how new the property is, you're going to have problems with your tenants that require your time. Fixing stuff that breaks isn't even among the top three most time-consuming things a self-managing landlord has to deal with. I think it would be a good idea to read a book on how to manage rental properties before you decide on a course of action.