I knew it - for someone who regularly writes tweetcarts I am strangely bad at crunching code. I strongly suspect I can take another pass at the ship drawing code and kill what is basically an entire duplicated block.
I'm really happy with the ship feel, the movement speed is directly linked to how much the ship is turned and the turn angle is governed by a proportional error based feedback controller which makes it nice and smooth and gives it the momentum/weight feel.
Anyone wanting a hard mode just needs to turn that r+=e/5 at the end into r+=e/20 for "heavy ship" mode.
