I've thought for a while that commuter rail lines:
Along the freeways: 35, 10, 281, 151
Between big retail spots: Downtown, Quarry, Rim, Stone Oak, 1604/Bandera, Forum
Big Business: Rackspace, USAA, Downtown (again), Amazon, Lackland AFB, Kelly AFB, Brooks
And new parking areas near big residential centers: Bandera/Tezel, Helotes, Boerne, Stone Oak, Great Northwest, Brooks City Base
Along with parks renovation, school improvements on the South Side and small business incentives would make San Antonio the best place to live in the country.
There's a lot of potential here.
Personally, I wouldn't move back without massive densification of the "urban" core. Right now the place is a massive suburb where getting by without a car is impossible.
I won't argue with your qualms on local government.
In practical terms, it would have been workable if my office had been along the Riverwalk. Otherwise, not really. SA's public transit isn't usable for white-collar professionals in most cases.
Besides Rackspace they have a bunch of defense contractors and USAA, but little else I believe.
It could be argued that UTSA is starting to count as a major university, with recent expansion and investments. But the CS program has yet to really prove itself.
Plus, SA has already played this game. It got them Rackspace. Which, uh, could maybe be going better.