I think this is quite excellent. It reminds me of a layed back version of the theme from Psycho (and, strangely, the theme from Young Frankenstein...). The violin is quite haunting, and works well with the overall effect, especially in tandem with the guitar (both performed very well in my opinion...not everyone is required to be a virtuoso when playing music).
It does seem like a bit of a cover, but nonetheless, I think it has enough going for it on its own to be considered a remix.
As for the tuning, I have no problem with it. In fact I quite like it. Whether it be intentional or not it (as was said before) it adds a lot of character.
(By the way, the bit with the cello and the guitar is brilliant!).