Basically, what I suggest is an articulated engine module which would work like turret mounts, but instead of mounting turrets it would mount engines that would also be built as seperate ships at first. Once the engine is docked it will always face the direction at which the thrust is applied. However, when in planetary gravity the engine will face downwards (and if it's powerful enough it'll make the ship hover, effectively ignoring the planetary gravity.). Also, once strafing and backwards thrust will be nerfed the thrust added from articulated engines will not be nerfed at the directions the articulated engine can face (sorry if that's a little hard to understand). Furthermore, the shields from the ship and the mounted engine are shared meaning that you can put part of your shield capacitors and rechargers in the thrusters and part in the ship. This, however comes with one drawback: the articulated engine mount block would be a weak spot and once it's destroyed, the attached engine will detach.