most towers aren't owned by carriers rather tower companies who lease space to carriers ,most towers have several carrier's equipment on them.
yes they are building thier own networks and phasing out the sprint tied services
This is what I heard as well. From what I was told by Cox directly (the people working in the stores), they purchased equipment from another carrier at an auction and have been spending the last couple years getting this installed, tested, and tweaked while they awaited the FCC approval to enter the market. I could have been told in error, but this was direct from the mouth of someone who works for Cox.
Now, the other thing I noticed and was not told by an employee, is they have added lots of smaller little branch outlets over the metro areas in Tulsa and OKC. Sure seems like they would be putting up brick & mortar retail locations more for wireless sales than in-home telecom services. Seems they also reference this in the news story:
"The company said it will unveil... as the centerpiece of its redesigned Oklahoma stores"