Is there a custom widget or some bits of code I can use to customize an edit widget that will show the angle of the line being drawn as well as the distance?
More ideas for an edit widget would be to have feature snapping (instead of pixel) and being able to move entire lines rather than each vertices. Those aren't priority for me at the moment but if anyone has a way to do this I'd appreciate it!
I would start by looking at these widgets
Those are more for drawing, but you may be able to find the code you are looking for to modify for editing.
These and other widgets can be found on the /blogs/myAlaskaGIS/2016/03/09/web-appbuilder-developer-edition-customization-resource-list