Nice build! I am no expert but I would certainly change some things.
I would go for a different case. A better case will normally include more fans which would help you from buying more and also help with airflow.
I would also swap out your cpu cooler with a water cooler.
My personal machine I am running a NZXT h440 case with the NZXT x61 kraken. In total the case comes with 5 fans I think plus 2 on the kraken and it is quiet.
Also I would go for a different gpu reference card. I like the GTX 1080 g1 gaming edition but I may be bias because I have it. Search up the reviews on the GTX 1080 series.
Well I don't know I've been told that mainly any of the GTX 1080 cards are great, but EVGA's is the best (of course they're apparently sold out and have been for a while) and just not to go for the Founder's Edition, and the Aero is considered awesome by a lot of people I've asked about it. But I'll certainly look into other video cards.
And thanks for the suggestion for the case! I'm no expert either so leafing through PC Part Picker's list of cases would have been a nightmare trying to find the right one.