Hey, I can't really help with all your questions, but I was told (not that it's the truth) at a MSC job fair that everyone gets their own stateroom, emergency leave "can" be arraigned, overtime is paid, 4months is the minimum shipboard time sometimes/most of the times it is more.
I would do a search on here, theres tons of info on the exact question in many posts.
Have you ever thought of cruise ships? I knew a guy from Vegas who was the IT supervisor on the Norwegian Star, another one on the Nor. Wind. Might be another option for ya. Better parties of that I can be sure. Not sure about contract lengths though. Here are 2 that I found at NCL.