I have laid my own tile floor in previous houses and they are supposed to pour a leveler if the floor is not level. If it is fairly level then the tiles should go down no problem. I only did square tiles so I cannot say on those longer skinny ones that look like wood. But there is ZERO reason it would not be level if the floor underneath is level. If there are tiles that stick up it is because the floor was not clean or the installer didn't push the tiles down like they are supposed to...you do NOT want an air gap between the tile and the floor. Only big concern I ever had with tile floors was the grout getting discolored over time in high traffic areas. We had a sandy colored tile and lighter grout so it was great after 10 years but I would recommend darker grout if possible. Not sure if saltwater splashes mess with grout colors...
We have been in this house about 2 years and we went with vinyl flooring planks because they do not care if you get them wet and they look like wood...and really easy to replace one if it gets damaged. We only have small dogs so no big dog scratches. I have seen some scuffs under the dining room table so I would expect issues under your tank stand over time. The vinyl definitely is not as tough as tile but I also dont have to worry about dropping a heavy pan and breaking the floor....yeah we never dropped a heavy pan on tile either.
Oh and don't be fooled by laminate flooring...no matter what they say they are NOT waterproof at ALL! Had enough in old houses over the past 20 years to know that they all suck.