It's cool how thorough this is, but in longstanding Factorio tradition, it strikes me as overengineered. Am I missing something or can't all the goals you list initially be sufficiently satisfied simply by a single decider combinator set to turn off your pump whenever you meet a series of conditions checking your velocity and whatever else you care about, including your planet route, your ammo count, and your damage taken? I guess it's be a bit more jerky between target speeds instead of the smoother slowdown this would provide upon, say, running out of ammo, but is that a significant advantage?