First: Thank you
Now, about your questions:
1. As I get it, it is just a meme. And it's been around some time. I just did it because I've seen other artists still filling it out.
2. I guess it is just this theme "Look at all the great, handselected artworks of this artist and in the middle you see the artist, the person himself/herself, surrounded by his/her works".
What artworks of yours the others get to see is completely up to you. I cannot see a specific pattern when I look at other artists' versions. Myself I just decided to offer a good mix to look at. If I would just display my recent artworks, there would be a lack of variety.
3. Templates? Yes, I spontaneously found these templates down there on DA. Myself, I just used Photoshop and placed the squares myself, no premade template.