My vision:
Ships take off and land from starports just like they do in the old
trav days. With a few details that have been left off:
The ship lifts on contra-grav until it reaches a safe altitude to
engage the drives at LOW power. The ship maneuvers to a safe area
(and continues climbing) and then throttles up to the desired
thrust level.
The flight path is heavily guarded by 'shore batteries'. Deviating
just may get you blown to smithereens. It also uses a nuclear
damper to help dispose of the scattered radiation of the drives.
The drives work just fine in the atmosphere, and even underwater
(like they used to do in the old Trav days...)
They can, if a pilot is crazy enough, be used to incinerate a large area,
and are possibly the most lethal of weapons.
However, any Referee worth his salt will not put the players in a situation
where using the drive as a weapon will be useful. And if the drive would
be useful it is not available. Also, if the players actually did
misuse the drive, then there are all sorts of nasty things that Referee's
can do to them.
Check your Traveller collections. You will not find a single adventure
there where a huge heavy weapon was needed and a starship drive was
available. (INCLUDING Double Adventure 6 Horde/Chamax Plague. The
ship was disabled and not flyable.)
MegaTraveller is a different story. There, there was call for heavy
nasty superweapons. But we aren't Playing that game any more. Now
there is no call for such weapons. So why worry about a weapon that
is basically useless?
Scott 2G Kellogg