For editing window and door openings, you right-click on the wall and click on edit framer window (or door), IF there is only one window or door opening, the dialog box will pop up for that window or door. IF there is multiple windows or doors, the FIRST one will be highlighted in BLUE. If that is the one you want, hit ENTER, otherwise hit TAB to advance to the next one until you get to the one you want to edit and hit ENTER.
As far as the headers to the underside of the top plate – that is on my list for very next feature/option. I used to HAVE to frame openings that way in my locality, but they dropped that a few years ago. Consider it on the list 🙂
Thanks for all of your feedback!