My previous post had screwed up links and I cannot edit it for some reason. So I post it again.
After long experiments, I came up with somewhat stable design for a ship. It is fast for the size, has 4 decks: farm deck (lower), Engine deck (middle), Living Deck (upper) and a small control deck on the very top. I have 50 forward engines and 16 turning engines (eight on each side). All the engines wired up to the control deck on the very top. I control the ship with 3 levers that do "turn left", "go forward", and "turn right". The altitude controller (to change height) and ship starter (to freeze the ship if it gets out of control) are also on the upper deck very close to the levers.
Here are the screenshots.