With regards to the cell phone ping in Gooding, Idaho. Some facts/thoughts to remember/consider.
1. The ONLY person who seemed to be aware of KB's "plan" to visit her grandmother in Idaho was PF. This info is in direct contradiction to the info that KB gave her mother about her "plans" (Thanksgiving dinner out with PF, decorating for Christmas) the morning of her disappearance.
2. LE is not searching Gooding, Idaho, nor are they searching Soap Lake, WA.
3. LE obtained and executed a search warrant for the home and vehicle of PF in Colorado. They did this while imploring PF to please come in for an interview. They also specifically stated that they obtained the search warrant based on facts, though unknown to the public, they'd gathered and presented to judge who felt those facts compelling enough to issue the warrant.
4. Remember LE photographed PF as well took samples of his DNA. I speculate that they used the photographs in various gas stations/restaurants along the route between Florissant and Gooding in attempt to show that PF travelled that route himself.
5. Consider that LE is in possession of KB's cell phone records, and most likely her computer, including Email. LE at no point has cast a "wider net". Why is that?
If KB were intending to visit her grandma, there would be a call? An email? A text? A google map? Our devices talk to one another now, when I search something on my phone, suddenly, I get advertisements for whatever that happens to be on my computer, and suggestions for hotels in that area on my iPad.
In summary, I'm willing to wager that LE has threshed out the Gooding angle and found that it actually pointed back at the the person who pointed a finger in that direction in the first place. JMHO.