I have the same things in my tank and also got paranoid about them, but they are just harmless flatworms, regular microfauna that come in and are actually good for your tank. When you have less algae, there will be fewer of these worms, but you definitely want copepods. I think you are on the right track with this tank.
vitaminsque 
As I understand it, the answer is to shrimp. Thank you.
I have the same things in my tank and also got paranoid about them, but they are just harmless flatworms, regular microfauna that come in and are actually good for your tank. When you have less algae, there will be fewer of these worms, but you definitely want copepods. I think you are on the right track with this tank.
just sign of a healthy ecosystem. nothing to worry about!
Just looks like rhabdocoela, which is harmless.
Yes, to shrimp. Those worms are normal. If you start seeing worms with pointed arrow shaped heads that’s when you have “bad” worms.