RNG Source Combining
Yes combining anything with the output of a good RNG will result in good random numbers (as long as they don't have information from your RNG)
Yes it would remove the bias (but there are other ways to do this whitening also)
No that doesn't really do anything interesting, but a simple way to unbias your numbers is a Von Neumann extractor


Also try to find non deterministic sources, be suspicious of random data from strangers.