The bridge looks good even without the support and no bulge, this is just what ships look like, they are flat on the front. I think the ship is beautiful.
Now put arms that rotate out top of the front raised bit and you got the perfect mass fishing ship also you should include some rope attach points all over for towing especially on the front
For the cargo trolley, I suggest having larger wheels. For the fishing boat, I'm still suggesting making it a stern trawler with the bridge on the forward superstructure. Nice video.
Have a look at some real commercial fishing vessels and see how they are designed, then copy one of them. Remember, your design decisions have to make sense, this is a practical vessel. You can't do things "willy-nilly".
If you could modify the container trailer, so the front is mounted on a pivot, then it would probably be alot smoother, and you won't have problems with drifting