The oscillator does not prove anything other than the oscillator is working and the TVP is not in reset. It is, however, critical that the oscillator is running correctly before any I2C transactions occur.
Next, do not write to reserved registers. Your code seems to write to all registers in the range 0 to 133 but there are many reserved registers in this range.
Finally, have you tried adding a significant delay after each read or write? Some transactions can take time to process and your software should really monitor the SCL signal to make sure it behaves correctly when clock stretching is required. As a test try adding a 5ms delay after each write or read to make sure you are not sending transactions without the required delays.
BR,
Steve