Hi Esperanza,
one important point to create a good addon, you need time for it.

You could build a good ship in a few Days, thats no problem, but to add it into the game needs much more time.
Lights, working Instruments, Bump and reflection maps or animated things like Doors, ramps....! Over these, you need a good Dynamic and collision. A good Lod modell is also important.
It's a nice Ship and I think it could be the first good addon with a modern Cruise Liner. So take the time you need.
And yes, if you need help, please post the problem. Here are a lot of experts for Ship design, Dynamics and much more. And I am sure that you will get help.
Regards
Thor