I think Star will have T-Series onboard soon, also Bhansali Films might shift soon to Zee or Star, still i believe Sony will have first right of refusal to let go or renew older titles same as with YRF.
Regarding Star Network, well it has acquired many films in past few years be it old or new and even dubbed content (hollywood / south indian) but at present some content is being repeated quite more bcoz these r moving to rivals. As all these things get sorted then schedule will feature wide variety of stuff.
Sony gets max ratings due to various reasons- it has strong brand connect so people tune in more (like mastiii, B4U), dubbed south indian films do very well in rural belts and Max gets high visibility there and thirdly it has some bollywood films with immense repeat value ..... All these contribute to surge in ratings. Star Network is strong in urban , semi urban belts, fav destination for bollywood fans in hindi belt and thirdly its viewership gets divided between Star Gold 1 and 2 which is not case with Sony