In our previous reports (Part I and II), we have identified precursor "supersaturation" as a key parameter to control the precipitation behavior of titania nanoparticles in a temperature-driven hydrolysis process from the chemical bath of soluble titanium salt. Through this protocol, a methodology was developed to grow titania films with controlled microstructures and phases. In this study, we deposited titania films containing anatase or rutile as a dominant phase along with microstructures of various film densities, which were characterized for their dielectric, optical, photoelectrochemical, and mechanical properties. Specific microstructures and the constituting phases were responsible for a wide variation of such properties of titania thin films. This study aims to provide the systematic explanation for evolution of the phases as a function of the degree of supersaturation, along with the discussion of their effects on the aforementioned engineering properties.