I'm having the same problem and am discussing it in a different thread. I still need to have the battery checked but if that checks OK I'll be in the same boat as you. That said, I'd like to see if I am getting the same voltage checks as you.

In the front of the same box as the RCM is connector C106. That connector has a wire in it that comes from the pulse module and energizes the starter - it is in position 6 of C106 (there are a total of 8 positions in this connector but only 6 are used). The "socket" side of that connector goes to the starter (Engine Side) and the "pin" side comes from the pulse module (Engine Compartment Side). You can take a piece of 14GA wire and make a jumper (I used 12GA ROMEX) and jump from "socket" #6 to the positive post on the battery and your starter should engage - that will prove your starter is good.

Then, with a DVM, read the voltage on "pin" #6 when the key is turned to the start position - it should be 12+ volts and should hold that voltage for a few seconds. Mine only has voltage for about a half of a second. Can you check your voltage there and see what you are getting?