scan1-scan2 is over-simplified, if you want the -shortest- difference between the two headings, which is more useful, it should be: `360 - Math.max(scan1,scan2) + Math.min(scan1,scan2)` I think. Different when dealing in radians (obviously).
The last question is a little difficult to phrase, but no I'm not talking about the absolute value of the heading difference. I'm talking about calculating the distance between two points on two given headings. Using trigonometry. Eg "where is the bullet the robot I just scanned just fired? if he fired one", I know this specific example is impossible to model exactly, but for modelling best-guesses of enemies' guns I would imagine this kind of equation would come in handy.
Thanks for the links to Lateral and Advancing Velocities, it makes sense that they're used a lot in the more advanced algorithms, but those algorithms are all pretty much magic to me at the moment so I had absolutely no idea what is and isn't used.
I'm also not asking for specific answers to these questions, just asking if it might be wise to set up a wiki page that has some basic physics for the purposes of other newbies who don't have answers to the questions (I do, because my dad teaches A-level physics). But thanks for your answers nonetheless, as they did help clarify one or two points I wasn't sure about. :)