If you applique the flowers onto a background make sure it has a firm foundation.other wise the shapes look puckered and it doesn't work. I found starch a good idea .
I would do single blocks and no sashing . You can then put smaller hexagon flowers on the intersections.if you leave room. This will. Look as if you have just worked as a whole.
I have just had an idea for option 4. Make a bargello background of green and blues for grass and sky. Then put lowers on and you could o stems?....