Hi Mau,
It's a really nice camera. I had a job yesterday that ended up with over 2K shutter shots in several modes, differing meter modes, mixing a variety camera options. It was a dream with the D7K, but to be fair, there are several Nikons that make such work pleasurable.
Be sure to spend a great deal of time with the manual, and try to figure out what your ideal work flow (enjoyment flow) will be with the options with the camera.
An example of that might be that you might want to 'control' aperture (A mode) and watch what the camera chooses for shutter speed, and adjust -/+ exposure compensation for perfect exposure. That would be the same for any camera, but you'll learn that as you learn 'where' things are on your camera, you can do it quickly.
Your 35mm lens gives you an 'angle of view' very similar to a human's eye, and a fast f-stop - like Cary, I have it and it is the lens that I 'usually' leave on the camera. For my taste, I wouldn't put a lens attachment to modify lens behavior for angle of view, but would buy another lens, either wide or telephoto or zoom. It's a much more expensive option, and I don't fault you for saving some money. If you are happy with your results, then good. But in the fullness of time, you might want to expand your vision. If you're young, you have plenty of time to save and grow your collection - there's an English expression that suits this: Rome wasn't built in a day.
Take a lot of pictures! Every picture you take makes you a better photographer.
My best,
Mike
