Medium-rare salmon with nothing else added will not do her any harm on an occasional basis. : ) It's awesome that she enjoys being brushed, many cats can get overstimulated with too much brushing or petting and will snap at or bite the hand in question.
Even though my cat is an awesome traveler, any time I have a new car or camper, I take her out to the new vehicle and spend time with her in the vehicle just playing, letting her bird watch . . . without moving the vehicle at first.
I'm not sure what Amazon has in the way of cat toys, but I have not met a cat yet that doesn't absolutely love a wand toy (the wand is for you to hold) and a string with two feathers at the bottom of it. When you move the wand side to side, the two feathers flutter through the air at the end of their string and very closely resemble a flying bird. You always want to allow the cat to catch and chew on the feathers a little bit, or this no pay off. You will probably also find that allowing her to catch the "bird" will prompt her to eat some of whatever you have in a bowl or dish for her. When they hunt and catch something, their DNA tells them to eat, even if it's a fake bird.
Midnight sounds like a very happy, healthy, loving companion. Supervising humans at anything they do is a cat's favorite past-time. Sitting on papers of any kind is part of the wiring, as is sitting on your hands or patting them if you have been at the phone or computer for too long.
When I was still working, I had a super long conference call every two weeks. For one of those calls, I had numerous jewelry projects on my dining room table, all of which I covered with dish towels to keep my cat from freeing the beads. After about an hour and 45 minutes, my cat got on the table and put her front legs under each dish towel and swept every single bead onto the floor. I was still finding 3mm beads a year later, they had become lodged between the boards in my flooring.
I think you will have a great time being a cat mom, they are unique critters with great personalities. I love dogs too; this particular cat will not allow any dogs into her space or life, so I do not currently have any dogs, lol. It wouldn't be fair to either of them.