edit: Okay, I should've read more carefully...
To sum up the process and see if I understood everything:
First, I want to worry about hitting my initial seed. (Easy, since non-C-Gear Seeds are easy to hit...)
Second, I advance the IV frame to get my desired IV's.
Third, I advance the PID frame to get my desired Naturne, Ability, and Gender.
Fourth, I capture / receive the Pokémon I want.
Damn, I can't wait to RNG my Shiny Snivy when I get Black! :)
edit2: Oh, I just noticed the OP says that you can advance the PID frame only by walking in areas with wild Pokémon; does turning not affect the frame anymore? That would make a difference...
Avatar by the amazing Yilx!