Just start training and racing like you're a 3 and get the points. The pitfalls of the other methods are obvious, but many have succeeded on experience upgrades. I just think you should be able to figure out how to beat the sandbaggers and everyone. Don't race the same race if you're not improving or finishing well. Change up your approach and never get caught repeating what doesn't work. Do get caught taking risks and being aggressive.
Just act like you're pissed that the USAC put the wrong number on your license and prove it. Every time you swing a leg over the bike or plan for a race -- what can you be doing to win your next race?