There was a discussion here within the last few months about a diagonal island, with lots of (imho good) arguments against it, most compelling of which were that it's too far across the aisle in the work area and too pinched at the corners and that it was also an inefficient use of space in the overall room. Based on lots of reading here over the years (as I'm no expert personally), you may hear suggestions along the following lines: move the fridge to the dining room end of the counter run, that way people at the table and in the living area can get drinks without entering into any of the kitchen work area. if you keep the fridge where it is now, you'll need a filler of some sort next to it or the door handle--and maybe the hinged edge of the door itself--will hit the wall, meaning that it'll be tricky to remove the drawers; consider a microwave drawer; as AFritzler says above, the lowers should be all drawers, which is vastly more useful than doors, even with pullout shelves; is the line across the garage the external vent for the range hood? Consider whether an inline or external blower and a silencer would work better for you in terms of quiet fan operation in an open cabin; do you really need a desk? With laptops and iPads and lots of seating, it may be space that could be better used for something else, also eliminating a collection point for junk. That's all I can come up with, but I'm sure others will chime in with better ideas.

Photo? Since it is a lake house, how about hanging several old wood oars? You could always paint them whatever color you want or keep the old color/patina.

I was thinking something similar to Shead. Some people know have a cabin on a lake in Canada. It has a large white chimney. Mounted on the chimney is a large black letter, which is the first letter of their last name.

I think you're going a lot in the wrong direction. Placing large planters to mark where the driveway stops and grass starts is unnecessary and wrong. Create a 12 wide mowing strip (like a little sidewalk of brick or pavers) and people will know. The circle business seems all wrong and the bed shape, too. I also don't think that putting anything tallish in between or in front of the rocks is going to help you. Just low groundcoverish type plants will be enough to nestle in the rocks. You cam make the groundcover a mixed bed of perennials if that suits you.