What's the difference between manga, manhwa, and manhua?
What you listed cover many of the major differences, though there are others.

Manga


From Japan
Multi-panel
Almost always black and white
Right-to-left


Manhua


From China
Full color with some panels rendered entirely in painting (1)
Single issue format (1)


Manhwa


From South Korea
Usually horizontal, left-to-right
Can be vertical, right-to-left, top-to-bottom (2)


(1) 

(2)