Concurrent filing of H1B Amendment, (new) H4 + EAD

Hi - Here’s our situation. My wife and I are on H1B visas. However, while I went through the lottery, my wife has a cap-exempt H1B and she has never gone through an H1B lottery. We have approved EB2 I-140 with priority dates in 2016 (me) and 2020 (my wife). But, given that our country of birth is India, we are far from having our priority date current. We are now planning to move to a different city, and my wife is planning to switch from cap-exempt to a cap-subject employer. To facilitate our relocation, I am planning to have my employer file for my H1B amendment (for the relocation to a different city) via premium processing. As part of this application, we are planning to concurrently submit an H4 and EAD application for my wife.
Our questions are:

  1. Are we able to submit H4 and EAD (for the first time) for my wife via my H1B amendment?
  2. Will USCIS process H4 and EAD in the same premium processing time period (15 days)?
  3. Are there any risks in this process/plan?