Greg, great info as always. You da Entertainment-man.
I expect they'll get the cab system refined. But it will never be perfect. The numbers needing cabs will vary greatly (a good example of a need for analytics), and as you point out, no driver wants to sit out at the Smith Center and not get a fare. As you're looking for a cab, hopefully you can buddy up and share with another party. Also, driver is also not going to be real happy about a fare to Fremont Street. That's barely a click on the meter.
The pedestrian bridges won't solve the problem, I suspect. Bridges in out of the way places like that won't get police patrols and will probably not be all that much safer than the Ogden via duct under the tracks.
Busses look like a decent option, though some of them stop serving the area at 11pm. For the expresses, which is what you want, will run you something like $7 a person.
Bus there, cab back may be the best option for those without a car.