Indonesian is an Austronesian language. Austronesian languages are spoken from Madagascar in the West to Easter island in the East and from Taiwan in the North to New Zealand in the South (hi Max and Cap K), but not for the most part in Papua New Guinea and Australia. According to who you believe the Austronesian languages may have spread out from Taiwan (some of the native Taiwanese languages are members) or from the northern part of the Philippines. Either way Indonesian is not related to the Chinese languages any more than it's related to English.
Whether the Indian influences in Indonesia stemmed from some sort of political colonisation or from a combination of merchants indulging in a bit of cultural colonisation of the indigenous elite is again a matter of who you believe. There's not enough evidence to be sure either way.
Bingley
