What I can say about Fairy Tail is, it started good, becomes better, then sliding down when hit certain arc, and keep sliding down. Even though its redeemed a bit (for a fan at least), because the few last arc are used to explain the background of character, that already mentioned from the start of the series.
Well about friendship thing, its shonen manga soo.. I cant blame it. Most of the old shonen manga like One Piece, Naruto, and Bleach using the same trope too in many situations. Its kinda like a patent or a must for shonen, or a series that want to known as a shonen.