Clean. Nice job!
You could drop the PSU to a lower wattage BUT I'd advise against that. The PSU you have listed now is 650w (which is plenty for most builds) and fully modular. That flexibility from the modular power supply will be very useful if you ever plan on upgrading components. Yes, you could go semi-modular, but the price will be very similar. Overall, though the PSU is an overkill for this build, it's flexibility will be well worth it going into the future (if you can afford the 30$ premium). If not, then I'd be switching it out with this one:
The third fan is up to you. Like casino11 said, it would be a recommended addition, but you can reposition the two fans you're given if you'd rather not spend the extra 10-15$. If you do add a third fan, I'd just buy another of the fans the case comes with (counting that you can buy those fans separately).
Speaking of the case, my last recommendation would be to consider the Fractal Design Meshify C White TG.
It's a very similar enclosure to the one you have, but is a more recent release and includes a tempered glass panel. If I remember correctly the Focus G has an acrylic panel. My experience with acrylic has been fairly poor. It doesn't look all that amazing out of the box, and that fact is only amplified as time progresses. Every acrylic case I've owned has had the panel replaced after a year or two because of the intensity of the scratches (after a while it looks really ugly). This is because acrylic scratches much, much easier than tempered glass. Because of that, I'd say that the glass addition alone is worth the extra 35$. Again that's not to say the case you have selected is terrible by any means, but it will age much worse than a case with a glass panel.
Another case you could consider would be the NZXT H500. It has a gorgeous layout with a glass panel and is a little cheaper than the Meshify C, but won't cool quite as well (by a 7 degree Celsius average).
I hope this answers your question.
What's that mousepad and headphone stand you're using there? Gorgeous build btw.