[tStano]

Okay! Thank you so much, guys. I really appreciate all the effort that clearly went into those posts, and I hope it can help many students to come. Definitely got me interested in a more softwarey path in school again.

NotInControl, your post really gives a good overview without me having to worry so much about the math I don't understand. That was super helpful, I much better understand what I'm doing now.
Austin, rereading your post after NotInControl's really gave me some awesome insight. It really gives a good overview of the involved complexity in designing a system. I'll look into some math, and I'm sure that will help my learning process with all this controls stuff.

So, a few more questions, which require an oversimplified explanation of my understanding:
1.You make a mathematical model of your system using all relevant states. It needs to be linear and time invariant or the math is even harder.
2. You use this to test your code which uses the variables you defined to achieve an output. You tune constants here. This is where I have questions. do you create some kind of testing code? Is hardware(sensors, even mock-ups of robot parts with similar moments?) involved?
3.Then you go to the real robot, and hopefully, its close enough to your model, and everything is peachy.