I think it would be easier if Blizzard would just change the UI so when you open your character with the C key there is another character pane right next to it that you can put your PVP gear into. That way you are wearing your PVE and PVP gear at the same time and get the benefits of whichever type of content you are doing at the time. When you get PVE rewards put them into the PVE slots and the PVP into the PVP slots. Easy peasy. No wasted bag space AND you keep earning your gear the same way as before.