Question on Horizon walker

[herrhauptmann]

Found Saph's Horizon Tripper build and thought of a question regarding becoming aligned to a dominant planar alignment.

Lets say I'm a Chaotic Good character. According to that, I take no penalty from Holy word (as well as a chaotic version of Holy WOrd). Take no penalty in planes that're dominantly aligned Good and/or Chaotic (but still would on a CE or LG plane).

Now, if I took 7 levels of HW and became aligned to Lawful and Evil, what would that mean?
That I take no damage from Unholy Word, blasphemy, (and lawful version of holy word)? As well as Holy and chaotic version.
That on planes that are dominantly Lawful, Chaotic, Good, or Evil, I take no penalties?

I'm contemplating my next character to be a horizon walker. Going to take at least 7 levels in it. Shifting planar. Cavernous planar (for tremorsense), and at least one of Lawful/chaotic/good/evil.
For nonplanar traits: Underground, plains, desert, aquatic/mountains (depending on stats and armor), and forest (though I'd like to check MM to see what counts as a forest creature).

Beyond that, no specific plans on feat selection yet.


Edit: Any particular opinions on my chosen terrain traits?