That wouldn't make it any harder. Sides only have a single orientation, with the opposite side suited to the center piece of one of the neighboring sides. Placing the piece with the correct neighboring side addresses the issue automatically.
Corner pieces can be rotationally incorrect, through the solving process, and is one of the harder areas to sove on the puzzle.
No, the center piece on a particular side has a preferred orientation with regards to the pieces on its left and right assuming the cube is like this, with S M G standing for the Samsung logo and o being a standard plain coloured square:
o o o
S M G
o o o
The M piece must be correctly positioned to align with the S and G pieces, if it is rotated the logo will look wrong. Obviously if they were plain coloured squares the rotation would not matter.
Corner pieces can be rotationally incorrect, through the solving process, and is one of the harder areas to sove on the puzzle.