Neither has been released yet, so how would there be any benchmarks?
No i9s (except for the 7900X) will be released until much later this year, so if you want to buy before then you don't have a choice.

If you're going to use it for anything that does use a lot of cores then you should look at benchmarks for that, since the difference will be larger.

If you're just going to use it for TF2 you might as well buy an i3-7350K, overclock it and get better performance than either at a fraction of the price.

To be honest by the time you actually scrounge up the money we're probably 2 or 3 CPU generations further down the line.

I don't care much about windows.
Windows 7 is Windows 7.
Windows 8.1 + classic shell is essentially a newer and slightly faster Windows 7 since you never have to look at the metro bullshit ever again. Except for some settings because Microsoft found the only way of making the control panel even more confusing by making some settings only accessible via the normal desktop and some only via metro.
Windows 10 is basically a fixed Windows 8(.1) and then a steaming pile of shit bolted on. Microsoft's way of getting more people to upgrade isn't to remove the shit but rather to put a gun against your head, which turns out not be an actual gun rather than them flinging more shit at you and is rather ineffective.

Basically Windows 7 if you want Windows 7, Windows 8.1 + classic shell if you can deal with the control panel bullshit and want something newer, Windows 10 if you want DX12 or want the newest.
Don't forget to apply the update fix mentioned above to 7/8.1.

Only one install away https://www.blender.org/

Remove the drivers completely and reinstall them. http://www.guru3d.com/files-details/display-driver-uninstaller-download.html
If that doesn't work remove windows completely and reinstall it.
If that doesn't work stop using Windows 10.

Cases are personal preference, due to asthetics. Dust filters should really be standard though at that price.
There's a few microATX options. There's the Core V21 that #2469 mentioned, which I usually don't recommend because the front panel ports are down low on the left side which means you basically have to put it on the right side of your desk and can't put it on the floor or anywhere else if you want to use those, and it's fairly wide which isn't ideal if your desk isn't that large. It's a good case though and rather cheap.
There's the N200, standard 40$ µATX case, 2 fans, mesh acting as dust filter on the front, can fit basically any GPU. https://pcpartpicker.com/product/T3rG3C/cooler-master-case-nse200kkn1
The usual Fractal Design Core 1000 USB 3.0 or 1100 and lots of other options.
A more expensive option with a window and some other stuff would be the Define Mini C. https://pcpartpicker.com/product/vBTrxr/fractal-design-define-mini-c-microatx-mid-tower-case-fd-ca-def-mini-c-bk

Just for comparision, you've seen 40$ cases that offer the same as the 200R, here's some 70$ cases to show you that the 200R really got no business being that expensive.
Phanteks ECLIPSE P400 https://pcpartpicker.com/product/xjZ2FT/phanteks-case-phec416pbk
Window, dust filters, RGB LEDs, much more interesting design, much easier to work with.
Fractal Design Define C https://pcpartpicker.com/product/gvbkcf/fractal-design-define-c-atx-mid-tower-case-fd-ca-def-c-bk
Sound dampening, dust filters, again easier to work with. While the P400 is going for "non-standard" lines to avoid being just another black cuboid the Define C does the "simple lines" thing really well. The 200R somehow attempts both and manages neither.

I don't think it's optimised for any CPU. I'm pretty sure the Pentium 4, which is in the official recommended system requirements, would actually suffer even more from the weirdness.

#1
Not possible.

#11
IPC depends on the program. Passmark is not TF2.
Anyway I've got an i7-4790K. I can't get 500 fps on 6s mids. Not even close. It seems rather unlikely Skylake would be massively faster in TF2 instead of the usual 10%. The benchmark thread agrees.
500 fps are simply not happening.
Then again you won't get 500 fps in any current game either. The problem isn't that you can't get 500fps, the problem is that TF2 needs a gazillion fps to feel smooth.

#2471
Watch a video to get the order right. Don't forget the mobo standoffs.
Test with just CPU + mobo + RAM + PSU outside of the case to check for DOA parts. Especially if you're using the stock cooler you can just leave it on afterwards.

#2472
GTX 1050 then I'd say. Maybe 1050 Ti if you can find a cheap one. RX 470/570s are sadly too expensive at the moment

There's better SSDs. https://pcpartpicker.com/product/D28H99/sk-hynix-sl308-120gb-25-solid-state-drive-hfs120g32tnd-n1a2a
200R isn't really good value. Full ATX case doesn't make much sense anyway.
Not a fan of Razer either.

I have been summoned.

Or it could be TF2 updates. Or overheating. Both vastly more likely. Since the USB cables didn't change.

CRC errors are handled in hardware.
Peripherals not in use do no generate signals.
If the signals from your mouse and keyboard can not be transmitted correctly you'd notice.

USB cables aren't made of some kind of magic.

http://www.novuslight.com/uploads//n/USB-3_Cable.jpg

USB2 uses only a single data pair so the common shield is enough.
On USB3 each twisted pair is shielded individually. If it's not your cable is shit.
The is no magic that a 25$ could add. Shielded twisted pair and that's as good as it gets.
Maybe a ferrite bead when the situation calls for it. https://upload.wikimedia.org/wikipedia/commons/7/73/Cable_end.JPG

Use the stock cables. If they are shit then your peripherals are probably shit and the cables are the least of your problems.

Why would anyone use the gigantic middle finger that is Windows 10? It was built around the bright idea "If a feature is so universally disliked that everyone disables it then a fix is needed.", which seems sane until you realise that Microsofts fix is removing the option to disable it.

I answered for others looking at this thread.
3/10 troll overall.

#2464
Google it.

#2465
Budget?
GPU doesn't help for streaming unless you're using NVENC/VCE in which case the quality will probably be worse than with x264 on a 3570K.

Casted by Bren, Bren and Bren?

Microsoft decided to not support new CPUs, starting with RyZen and Kaby Lake, on Windows 7 and 8(.1) anymore.
As official support does just about nothing, everyone ignored that.
Therefore Microsoft decided to block all Windows updates for those daring to use a new CPU on Windows 7/8(.1).
This has been widely considered a dick move.
So someone called "zeffy" made an unofficial patch that simply removes the functions that Windows uses to check before an update whether or not the CPU is "officially supported" on Windows 7/8(.1).
https://github.com/zeffy/wufuc
That should fix it.

Because fuck Microsoft, fuck them for pulling this bullshit, fuck Windows 10 and the horse it rode in on.

You haven't had the pleasure of playing against eastern european / scandinavian scouts.

I am convinced that it's no accident that 70% of the top scout have retardedly bad internet connections. I swear these things happen way to often to be just dumb luck.