I'm super excited to say that I've saved up enough money to build my first (real) gaming PC! No more dealing with an overheating laptop :D

I've built a PC for a friend before, so I have a pretty good idea of how to build one. My questions are about the hardware. Here is my build: http://pcpartpicker.com/p/vxg2qs

One thing I want to mention is that I will not be ordering any of my parts, I'll be physically going to the store to buy them (I've had packages get "lost" at my place, I would cry if that happened to a PC component). So, I'm restricted to what my local store has. I've done some research, and I've decided that this is probably the most "bang for my buck" build I can do within my budget (no more than $600). So, here are my questions.

1) I've heard the cooler that comes with the CPU is Very Noisy. Has anyone had experience with it? If it's true that it's Very Noisy, what would be a better alternative?

2) What sort of quality will I be able to get when streaming? I'll mainly be doing low-demand indie games, but it would be nice if I could do Fallout 4 or GTA 5 with decent quality.

3) I have a WD hard drive in my part list. I know the Seagate is cheaper, but I've also heard people complain that they end up with hard drives that are dead on arrival, or die after 6 months. If I go with Seagate instead, what are the chances of this happening?

4) Is it super worth it to go with 16 GB of ram, or would I not notice a difference when gaming if I go with 8 GB?