No it is not weird to have anime characters as your imaginary friends. Just know the boundaries of reality and fiction.
You could imagine someone who tells you the right answer. whatever you want.
From watching the anime I believe they are just good friends. they are both main characters in Fairy Tail, if that is the anime you are talking about.
Websites that offers a database of different anime characters are Anime - Plant, Anime Character Database, Anime - Source, Absolute - Anime, My Anime List, Anime News Network.
Cartoon Network.
Anime fanfictions are fan fictions written about anime characters.
Cosplayers or Anime Characters? Cosplayers are still human beings so they can. Anime Characters in an anime can go to hospitals if the story calls for it.
http://serebii.net/anime/characters/
Try the Anime Characters Database and type in your choices and it will refer you to anime characters based on your attributes - see related link below .
You could consider Grand Chase an anime - video game cos the the characters are also anime based.
Anime is a form of fantasy and so the characters will resemble people that come from the artist's fantasy, often their own ideals. Add to that the societal value of slenderness you will have the over-exaggerated anime body proportions of super skinny characters.
Anime characters, people who live in story books, people who cosplay anime characters, people whoo have wigs, and people who die it that color.
No there are not any characters called tegan.