Steve has not indicated that he's adding any sort of system that would allow tens of Gs of acceleration.
Tens of G of acceleration are a fact of modern day technology, an ABM has acceleration over 100G, in fact. Ruling them out from manned ships is possible, but the issue will reappear for drones and missiles.
As for cruising, that's not the case. If you have the delta-V, it makes sense to burn constantly.
Not necessarily. Burning constantly will send you "there" faster, but it will also use more fuel, and might make sudden course changes more expensive. Again, for a cargo ship, on a predefined route, it makes sense, for a military ship on patrol, not necessarily so.
And why is maneuverability so important, anyway?
Can think of many, but in a nutshell, because maneuverability=acceleration
- In a missile vs antimissile dogfight, better acceleration will always win (and if the incoming missile manages to evade the antimissile, it will need to maneuver back towards its target)
- higher accelerations allow an antimissile to reach its target earlier, which is important if warheads are area weapons.
- In a long range ship vs missile situation, a ship with good acceleration can (perhaps) create a situation where the enemy missile runs out of delta-v, lasting longer may matter
- In a more classical (moving) ship vs ship situation, before you fire a missile, you need to align with the target. Better ship maneuverability will allow for an earlier firing solution, better missile maneuverability will allow for a larger set of solutions.
Francois