1. I felt like masking the image was easier than refine edge.
The advantages of masking was the quickness of doing so. A disadvantage I could see was have to refer back to the image that was masked to refine some areas that were not masked.
I felt like the refine edge tool allowed for softening and blending the images edges, rather than define them.
Challenges I had were simply getting used to the tools.

2. With the puppet warp tool, I intended to move the cats right paw nearer to the ball he is playing with. I really like this tool! I can see it be useful in many situations. Very cool!

3. I would definitely use the quick mask tool in the process of trying to shadow an image.

4. The channels panel section was kind of confusing at first, but after trying it out a couple times it became easier.
I would probably use this tool in future projects for shadows and altering backgrounds.

5. I am regularly using command z, zoom in, zoom out, save as, and save.

6. link