As to handle time. The times that I know I am on the Elite line I have never been pushed off.

As to the reward ticketing changes. I was recently in SFO with two of us flying one on reward ticket and one on paid ticket both purchased by me PLAT. After an unfortunate issue in SFO I had to change our return tickets several times. Never had a problem or issue with the reward ticket. My ticket on the other hand was painful to change.