Brettski,
ewest hit on a couple of important things, windows facing the pond, breezes and sun.
I have a small balcony overlooking the pond that is almost never used, yet I constantly use the windows overlooking the balcony. I spend more time around the pond at ground level and I will bet that you and your guests will also.
Placing the house on the property to take advantage of breezes and sunlight are important issues as well. I covered the breeze part to the extent that AC in not required, even in 90 degree weather. But, I failed with the sun. During this time of year the sun is so low that it shines directly into the windows overlooking the pond.
If you keep the patio, I would put it on the ground; we solved the food service problem that I guess is one of the reasons you have the patio upstairs, by adding a small outdoor kitchen on the patio. It has turned out to be the most used part of the house. I would also move the upstairs rooms to the back or side away from the pond. Might look out of balance on paper but when the pond is in the picture I think that balance will not be a factor. You can also add balance with landscaping. Try painting the house white, in your drawings, and adding some trees, that may help give you a better perspective.
For the resale aspect you might consider putting this building on hold and design the main building first. Then use the exterior design features you used in the main house in this building so that when you do build the main house, they will be compatible.
