I would leave the counter tops and paint the wood that sits above and below the counter. The super-dark wood is keeping this space dark. The counter top is the most valuable surface out of the three. Remove EVERYTHING that you want to replace. Declutter so that you are looking at a clean space without decor. That means Taking down the drapes, emptying the walls, removing the rugs and taking down the Seasonal decorations (and the animal heads). Put the furniture pieces BACK into place and then take time to think on it. Remove the THROW blanks and any decorative piece you have. Just large pieces of furniture and blank walls. Now you take photos and mull this over. You will want to leave this blank for a while. Inspiration will come at some point, but only with a blank slate. The current decor is getting in the way of a new vision. And if you think you are going to add in gray paint, you will want to cover up the celery coloured walls with white primer. The green is working with the tiles (which are creamy peachy/pink). Be aware that a tremendous amount of your colour decisions will come from that massive slab tile. And gray doesn't always play nice with most of your permanent fixtures.

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.

I was about to say "keep the elevator, no matter what" until I saw the pic of the elevator in the bedrooms. Kinda kinky! :-D Seriously, elevators are wonderful at vacation homes, but that particular arrangement is pretty odd. Maybe for now the elevator could be parked and disabled on its lowest level, closing in the surround, and the surround on the upper level made into a closet, or something?? Meanwhile, although I'm not a fan of the red panels, replacing/restoring them with glass might then make the asymmetrical window layout start to bother you. I'd try to find someone who can do a good 3D rendering of the exterior before making any $$$ changes. I kind of like the olive green, although my tastes would perhaps tilt more to a sage green.

Do you want the secondary structures to be features or fade away? I could see all the secondary buildings painted black with the Maine house painted grey with white trim and yellow doors, or the same paint scheme on all. It just depends on the feel you want. The secondary buildings are less finished (trim not as resolved etc) so I lean toward monochrome on them.