My Propsal for my 3D games modles

The title of the game is Escape from Pirate Island it is a Pirate theme based game. The player starting on an island in the middle of nowhere and try to escape without dyeing by only using the weapons the player finds all over the island.  The target audience for my game is male and females from the age of 16 plus who enjoy FPS games with friends or on their own.

The technical restraints will be the polygon counts I have to try not to make it to high but high enough so when the image renders it won’t take too long but I want it to be to a professional slandered. The file type will be ever .3ds or.obj the .3ds is a type of file for 3Ds max and the .obj is an object file. but for my sword it will be up to  200 polysgons so it can run in Unreal Engine my ship will be about 2000 polygons and my island will only be about 1000 polygons the max polygons the Unreal Engine can handle is 2000k polys which will make creating my props, ship and island quite easy.

With the island that the game will be on will have the most lighting and texture and the modelling will be in high details. Unlike the ship which will not have much lighting or texture used but the details used on the model will not as low as the lighting and textures. As for the Golden Crown it will have less light and details as well as texture because it will be so small.

With this game I need to make sure that I am not breaking any copyright laws by using images as a reference for example using a pre-made model and just adding to it. I need to put that it is a pre-made model as well as which website I got it from. There will not be any race or sexual discrimination in my game.
Here are the screenshots of my mind maps for my ideas.