What version are you using? I'm on r121.
To make it slow down when not thrusting, turn the linear damping up, it's a variable underneath the physics behavior.
Im currently using the free version that is 119. I figure Ill get the paid version once I get the hang of it again. And it seems like the custom movement overrides the physics engine.. Im not sure what is going on haha.
Thanks for all the help tho, very kind of you to take time out of your day!