I love this class!
But I found something that doesn't add up...
Walk the Planes (Su): A Planeswalker’s greatest talent is the ability to travel the multiverse through sheer willpower. <snip> with a maximum of 4/day at level 16.
And on the table you have it going up to 5/day at level 20. I'll let you figure out which one is right.
Also, for spell lists, think it might be easy to consolidate each separate school of thought and magic (psionic, druidic, clerical, arcane, etc. but mostly the schools of transmutation, evocation, destruction and the like) into different pieces of the color pie, rather than trying to compile a list of names? That way no two 'walkers of even the same color would be of the same (See Jace and Tezzeret, or Liliana and Sorin)