NUG has been too naive. The main difference between Myanmar's secret police and that of the US or Western Europe is that the Western World has been much better at hiding the ugliness.
I don't like secret police forces either. But most of the world has similar. And with NUG and ethnic armies being active, Myanmar has more need for these than most other nations. As long as the warfare continues, you will just have to accept this.
If you can stop the killing, then you will have the possibility of neutralizing secret police forces. Other nations have moved from dictatorships to "democracies" (such is the goal, anyway), but they did it with a gradual process. If you try to accomplish too much at one time, you will wind up with nothing.
Aim for a cease fire to seriously start the process.