Brettski,
It sure sounds like you have put allot of thought into it and have a good idea of what you want to achieve.
Do you have a start date for building?
If you're happy with the design and find it attractive, then that's all that matters. The views from the inside should be amazing. If you'll be happy with the view that you have of it from the outside and feel that it adds to the beauty of what you are creating, then that's all that matters. Every building that you construct has the ability to enhance the setting and make it just that much nicer.
Another advantage to your plan is that a simple box is always cheaper to build then any other shape. Adding architectural detail adds more money to the build. If done well, the building can be as beautiful as the setting, if done poorly, it's an eye sore that becomes a disappointment.
Keep an open mind and spend time looking at as many plans as you can. Be willing to scrap one plan after another until you find the one that you will be the most happy with. Even though it's a short term guest house/ shop that you are going to build first, the nicer you build it, the more it will compliment your property and the next house that you build.
Eddie