What does the Sun look like from the heliopause?
0.004° converts to about 14.4 arc-seconds.
That's within the range typical for Mars; 5-25 arc-seconds. 
You'll see the sun as a point with the naked eye.
Heliopause is about 14 billion miles out. Absolute magnitude of sun is 4.83.
14 billion miles = 0.0007297pc.
Apparent magnitude will be -15.8543. Magnitude of the full moon, from earth, is about −12.74 
So you'll see a point source of light, brighter than the full moon.