Boost is an awful, terrible "mechanic." I honestly dont know how it made it into production.
Boost should be replaced with Afterburner. Same speed boost, but constant. Afterburner should build heat and burn fuel steadily while active, allowing the player to burn as long as THEY decide its tactically worthwhile to do so. Afterburner is a simulator mechanic; boost belongs in a game. Which is odd, since its the only real game mechanic Elite has at present...
Yes. I am trying to remember if the original elite did. It's been a long time since I last played it. Afterburner could be used in much the same way, regardless, and is more in line with what I'd expect.