Hello and welcome to JustAnswer!
It sounds like your problem is in the steering column. There is a square metal driveshaft that engages into the ignition switch, this comes from the lock cylinder and is what actuates the switch when you turn the key. What happens on these is this square drive piece will break and it doesn't allow the ignition switch to fully go to the crank position and the starter doesn't crank.
What you'll need to do is remove the ignition switch and take a look at this drive shaft, making sure it's intact. I doubt it will be - if by chance it's ok then you have a bad ignition switch again, but that's unlikely.
You inserted a screwdriver into the back side of the switch, turned it all the way forward (where it's heavily spring loaded), and there was still no power on the yellow wire?
The pink/black wire in pin 3 isn't related to the starting circuit, it's an accessory power feed. The start circuit is powered from the red wire in pin 7, which comes from fuse 14 in the power distribution center.