I curious to understand how it is you know what "cat food" tastes like. My daughter has two cats and I can't even get near a can due to smell!
Anyhow, I prefer to use Pacific Mahi Mahi allbeit both that, and Atlantic are a bit oily for my taste. As far as temp, after starting work in Atlanta almost 30 years ago, I prefer to not serve fish well done. The standard back then was med or just above since anything past allows the fish to get too dry. Maybe that's some of the problem with your experience. Writing from memory, I've never served it in "steak" form only filets. I would always cut the filet on a double bias to mimic the tail portion since that was the cut most people believed was the best. The flesh should be light redish brown to redish tan, almost translucent but not near a dark brown. There are specks of red, like lines on a hwy running the length of the filet on each side. On fresh pieces, these are a nice red but they disappear and become that dark brown I mentioned the longer the filet sits around. This is where the fish loses it's "sweet" flavor and can become bitter. Beef you age; not seafood, chicken or pork.
The bones are easily removed with a pliers and tend to be in the center fold of the filet. Be careful not to mangle this area because that can cause the fish to "split apart". I've done some cuts that were not a double bias and the best way to explain how it looks is picture an old tyme mustache. The fish should smell "sweet" with no other odors.
There have been many ways I've seen and served it. Given my exposure was more "Pacific" in nature, I tended to keep that theme although there are several methods. My favorites are;
With a mango beurre blanc
Macadamia nut crusted with a fresh tropical fruit salsa
Topped with Ponchatrain sauce (substituted for Red Drum)
Marinated in Pineapple juice, lemon Juice, ginger, garlic and soy and served as a sandwich
Sesame Ginger crusted
Roasted with garlic and Ginger and served in a miso broth
and finally, Blackened (again substituted for Red Drum)
Sides are paired with whatever the preparation method;
Basmati or Jasmine rice, Roasted Maui Sweet onions, roasted Maui purple potatoes, dirty rice, grilled vegetables, Baby bok choy and shiitaki mushrooms (this went best with the garlic, ginger, miso prep and served with Jasmine rice). Anyhow, it's up to you and your tastes or what you believe the customer base will respond to.