Aaron, here's my thoughts:
Wall tool
User to input profile details [width, height, Layer, etc]. As you build the wall sequence, each segment is 'grouped' to allow for individual edits in future. [I've attached a quick vid of what 1001bit tools do. It's not bad but does require additional user input to draw on axis as well as snap cursor seems a little 'loose' unlike the SU standard...]
2012-01-31_0819.swf
Just on this topic, I believe a plugin's operation and UI should be identical to that of SU. It would just make the users experience seamless....
Now with wall segments. Give the user the option to either build walls with Mitre or butt end. The reason is so the user can edit a particular wall segment individually. Eg: extend wall segment vertically to create a parapet wall or rake a wall top to follow roof pitch....
2012-01-31_0833.swf
In addition to the Wall tool there should be a Wall Edit tool to change from Mitre to Butt end for unique situations. This should be very easy given that such boolean operations are able to be done via Solid tools.
[image: T9xS_2012-01-31_0851.png]
I'll post more on windows, doors, etc later..