Trying to be both a LCC and a World Class carrier is impossible. It's like trying to play Basketball and Ice Hockey at the same time. You won't succeed at either.
AWA did a pretty admirable job against WN compared to many other carriers. It faced them longer and more directly than any other major and still made money doing it. When it combined with US, it was compelled to keep the pipelines of cash flowing (i.e. regional feed from every podunk city, a small international presence, congested hubs) even if all those pipelines weren't profitable. It was the complete opposite of what United did with TED (trying to add LCC to a legacy rather than add a legacy to an LCC) but with the same dismal results.
To be a major international player would require either bootstrap cash (none to be had) or merging with a major international player (who probably already has what US could offer, except cash).
To be a dominant LCC would require much higher utilization, the abandonment of distracting elements such as the small international operation and the immense regional feed and a complete overhaul of the contract and the way crews are paid. Even then, you'd have to prove you can run a reliable operation before the cash runs out.
I would say the best alternative is to split the airline up into two airlines that serve entirely different audiences. Before you say "that's TED all over again" there would be NO overlap. It would be like Southwest operating side by side with Lufthansa. Take the best of the LCC and the best of an International Airline that made no pretense about serving places like Duboise, PA with a one-stop flight. International would operate out of high-yield cities only not hubs (different from LH, I know). The International side would be O&D only and the LCC side would rely very little on hubs, but serve high yield domestic cities with great frequency and go point to point. Regional airlines would be spun off as independents and could time their flights to coincide with LCC or International Arrivals and Departures, but they would assume all the risk.
Bringing back the old USAir is never going to happen. Building a successful airline (or two) out of what's left over from the old one and AWA might be impossible as well, but it might be the only strategy that stands a chance of success.