You're absolutely right about the blurry outlines! Thank your very much! I removed them as you did and her face is much cleaner now.

As for the lighting, I think I prefer A because, well, cats are furry creatures, putting too much light reflection on her body make her glossy like a smooth surface. Still I preserved a bit of reflect at the back of her neck because I remember that place on a cat is were light usually reflect. Can't be sure though, since my own cat died last year (old age) I don't have a real reference.

I also added some pattern on the floor to make it less plain, and also to make clear that it's a rug and not a table. The pattern shimmers in the dark because... I want them to! xD

Well, I'm no expert either, but I can give it a shot.

http://i.imgur.com/AlDRBCl.png

In the first image, I pointed to the spots. If an outline color is too close to the color of the form, it doesn't work as an outline, but instead blurs the figure--that is what is happening on the side of the cat's face. The other spots just have a small highlight or shade hugging the outline.

With those, it is tough to figure out how to deal with them. First I just got rid of them to see how it would look (A), then I just increased them so they are more clearly there (B), then that didn't make sense to me so I tried to edit them as light might actually fall on the forms of the cat's face (C). I also darkened the shadow in relation to the floor, to increase the contrast.

If I were making this picture from scratch, I would either many pick a less harsh highlight and just add it strategically to 'raised' areas to make them pop, or cover much of the cat's face with a highlight--depending on whether the cat is supposed to be in direct sunlight or something. Maybe better would be to use a shadow color a lot, and leave the color of the cat's fur as its own highlight--just designating form by the shadows.

I don't even know if A or C looks better.

Would you mind pointing the specific part for me? And maybe how I can improve it? I do know the theory but putting it into practice is not as easy as I thought... >.<

And thanks for the compliment, I got quite a bit of experiences about receiving such "gift" :)

There's a bit of banding--colors hugging the outline, in this case.

I like the shapes of the cat and mouse.