RE: Do I need this stuff?
I've been building airplanes for more than 45 years and I don't see paying money for these things.
As to CG, setting up according to plans is only the first step in trimming an airplane and it only has to be close. Then you need to adjust it based on flight performance. So what I'm saying is that balancing on finger tips is close enough for the first flight and then you'll adjust from there based on flight testing.
Controls throws are the same sort of thing. Mfg recommendations are just that, recommendations. Use a ruler to set them. Fly it and see how it feels. Adjust from there. Do be sure to go back and make sure that both ailerons have identical throws. Again, low tech is plenty. A dime store ruler works just as well as some fancy gauge to make sure that both ailerons or both elevator halves have the same amount of throw.
Spend the money where it counts, radio, engine, aircraft, ...
Dave