Your diagram comes out at about 114.5 x 101.8. A king bed (not CA king) is 76" wide x 80" long. Measure your mattress depth. If you want to use the 114.5 as the width of the quilt you have an overhang of 19.25" on the sides and 21.8" at the bottom or at the top (don't know how you want the quilt to lay on the bed - depends on whether you want a pillow tuck, whether you have a footboard, etc.) For question 2, I would wait until the rest of the quilt is put together and then make the decision. Generally I lean toward scrappier.
I don't usually design a quilt for a specific bed - might be better if I did - but since you are doing that, you might want to consider where the 9-patch blocks are going to be when the quilt is on the bed. It looks like they will be just off the edge on both sides. Their position top and bottom depends on how you place the quilt on the bed. Just something to think about...