A little question, who is the elven character and what are reimu's and rumia's relationship with said elf. Is he from final fantasy? o -o?

He's a legendary RPer. Basically someone that became popular on a MMO message board.

Alternatively, you can just click on the ? next to the Buront tag.

Or the Iron of Yin and Yang then read pavlov's comics

But don't expect to see this in the comics...yet(maybe)

If I don't know Touhou, I would call this a prefect family picture.

Is this picture fall into 'heart warming' tag category?

If you feel it's really that good then yes.
Just don't feel obliged to add stuff to pools just for the sake of making them grow.

They DO look like a happy family.
Looks so perfect...