Hi bulbousbow77,
The site standards state that the whole ship must be inside the frame. If a part of the ship is clipped, even if it is a very small part, the photo generally gets deleted. The photo on the mainpage, of the VEGA, shows the ship's deck. Those photos does not need to show the whole ship. Some sub-categories doesn't require the whole ship to be seen. The Ship's deck category is one of them.
As for the sharp photo being deleted. That has happened to me too. I've had a couple of, to me, sharp photos deleted for not being sharp. Determining whether a photo is sharp or not is unfortunately subjective. Some think a photo is sharp while others think it isn't.
Regards