A photo might help others give suggestions. I will leave it to others to comment on what the proper size of shutters is and whether or not certain houses need them. Your question was whether or not you should have working shutters. In my opinion, working shutters are only needed in two situations. First, if they would be original to the style of house - for instance you buy a 100 year old farmhouse that original photos show with working shutters. Second, if you live in a part of the country where working shutters are necessary due to the weather or other conditions. If you don't need hurricane shutters and your home did not originally come with working shutters, then I don't think they need to work and you could go with ones that are non-functional for appearances if you want them.