Yes... starighten the horizon, but I don't mind the rule of thirds here. The wonderful colours are just so amazing that you wanna looka at it as long as possible and I don't care that the rule of thirds is not here... Great picture!
I would straighten the horizon and crop off some of the top to elminate the blue sky. Blue is no normal it takes away from the rest of the image. The horizon somewhere near the top 1/3 would really make it great.