1. The Hitchcock touches are more muted here than in a drama of dark shadows and menacing music. There is the exotic location of the lush location of a room filled with dishes and a maid at the door. I thought it was room service in an hotel at first. The silky covers on the bed that flopped around regularly with one eye in close-up to tell us what the husband doesn't know and the boredom on the face of the unshaved man as he plays cards in the room that requires scaling the love seat to walk around.
We learn that the couple has been in there awhile and they are messy. We know they are wealthy from the size of the room, the bedcovers, the existence of a love seat in a bedroom. The man seems to be uncomfortable cool, as a bedroom would be at night, because he wiggles on the floor as he sits playing cards, bored. We know the time is morning because of the light through the windows.
2. I don't think this is a typical opening so far although Hitchcock seems to be moving away from the crowded public places we saw in the silent beginnings. Then, with Rebecca, there was one voice, disembodied, followed by two people. It was unknown, at that time, that the place was the south of France and since Manderley was a ruin, it seems hard to call it exotic. With SOAD, there is no exotic locale, the crowd is a few boys in the street, and one man lying on a bed in silence, soon to be joined by a loquacious landlady. All are different, but the brightness of Mr and Mrs Smith contrasts starkly with the darkness of scene and darkness of mood of the others.
3. I think they are well cast. Carole Lombard is mischievous from the beginning, hide and seek, come and find out if I'm awake, but not willing to give up the game until she thinks he stopped playing and left her. Then, she is hurt and worried. Robert Montgomery is good as a harried husband already in the first five minutes. He's bored with the game but sticks with it. He starts to wake, changes his mind and thinks of himself first, and then tricks her with the door. They are deep into game playing with different personalities and different styles of playing.