Well in answer to your question of making your ship stop moving forward in a straight line, have you tried right clicking on your ship and bringing up a menu that way? perhaps it has the option to stop there.
I tried the game a month back and frankly i wasn't impressed, i'm still waiting for a space game where i can design and put together my own ship, walk around inside it, be able to look out of the space windows, hire and actually need a crew to make my ship move if its large, explore and find new planets, land on them, walk around cities on said planets seeing weird alien cultures, and being able deliver 20.000 tons of water to the cactus people of desertron IV, as far as space games go it seems none of that is yet possible, elite frontier was the last satisfying space game i ever played, it's been close to 20 years and i'm still waiting for the next one.