#1. I like the background, but the main subject (the cat) doesn't have the same amount of contrast as the background. Also, you have a nice backlight running all the way down the front profile of the cat from his ears down to his chest. I would find a way to take advantage of that "cat-shaped light", by perhaps darkening the rest of the photo and highlighting that feature.
I hope you don't mind, but I had a quick go to show you what I mean:
You can see that I've taken advantage of the backlighting on his fur that I mentioned and made that familiar shape of the cat's face the main subject of the photo. Everyone is familiar with that serious look of the cat's profile, and the darkened background makes it instantly recognisable. We don't need to know where he is, the background wasn't interesting enough, but now
he is all that matters in the frame.
To highlight it even further, I changed the orientation to portrait so that the shaped of his face cuts the frame almost in half.
You could go further and blacken out the background in front of him completely, but I was hesitant for fear of over doing it and making it look un-natural. Perhaps you could have a go and see if I was right?
#2. There's some cheeky selective colouring going on in his eyes! I personally don't like selective colouring (we've all done it though, at some point in our exploration of Photoshop!) and this doesn't work very well since his eyes don't have a very stand-out colour, so it barely looks any different which makes it not worth bothering. I think the conversion is pretty good in this photo but the composition itself doesn't really lend itself to black & white.
I hope that makes sense and helps a bit, or at least gives you some ideas of how you can manipulate a photo to show what
you want the viewer to see. If something in the shot isn't important to the main subject or doesn't help to show it off, cut it, crop it, clone it out or find a way to get people's attention away from it and onto what you took the photo
of.
The shot was of a cat. Therefore, the cat is all that matters!