Of the back row, it's the hardest piece for me to find a use for.
I'm also afraid of positions like r1bqkb1r/pp2pppp/2n2n2/2pp4/2PP4/4P1P1/PP3PBP/RNBQK1NR b KQkq - 2 5
I Generally use it on the light squares.
Good answer, #2! Also, this question is far too general to answer, really.
It is more difficult to find good squares for the Bishops than for the Knights, that is why you should play the Knights first.
Theoretically the best development is the fianchetto, i.e. g3 and then Bg2. Even if the Bishop is developed elsewhere Be2, Bb5 it often comes back to f1 or f3 and then g2 later, after castling o-o and Re1.