Part of the problem with Bc5 is that they can respond with Na4, which threatens the bishop and grabs the tempo. Be7 isn't great because its range is inhibited by the knight and it impedes the kingside rook's power on the e file after you castle. Bd6 is nice because it is protected by the pawns, itthe bishop can be retreated to b8 or c7 while still controlling either of the second longest diagonals. I'm a 1500 rated player, so take that into account.