SomeTeenThatLovesComputers

Its possible, but you need to dive deep into ebay and other sites selling replacement part in order to find compatible screen. Considering age of that laptop, LED is out of question. But you may find 1080p one if it had 1080p screen versions sold, or if they used same panel design across multiple devices.

Quite beautiful. Personally I would've gone with an all-SSD build because of the silence

If you're downloading from old/slow servers than you're going to be bottle necked by their infrastructure not yours. What happens when you try and download something off a new site like Steam/Battle.net ect? 
 
Have you done a speed test yet? http://www.speedtest.net/ to see at least a base of what your hardware and your ISP can deliver. 

I have a build for that too! a "gaming" computer from the early 2000s with a 9000RPM Thermaltake CPU cooler!

A custom Antec SOHO desktop. Older than me. I don't know much about it because I cant get it to run any old OS (and issue identifying IDE drives because of some RAID Array problem?) What I do know: It has a 750Mhz AMD Processor (either Opteron or Athlon II) with a Thermaltake VOLCANO 6 Cu+. It has a GeForce mx2 graphics card, Turtle Beach audio card, 500MB-1GB of DDR. And I believe I saw these fans in one of Linus's videos. They are extremely powerful and loud. Yet still best all the new modern fans. This PC is pre-PCI era tech. Got it for free as well as a ton of 2004-2008 Gateway and eMachine desktops plus a few old laptops from the 90s. (One being an old Thinkpad I cant get to work )

Toughie. Depends on which you want more. Faster refresh rate, or better resolution. The 2k monitor should be just fine since its 75Hz. But if you are more into gaming like CS:GO and other FPS games I'd go for the 144Hz

Either card will go through Space Engineers as well as it can and GMod and CS just fine. Get whatever's cheaper.

Get terminal emulator. Run the command top and see what process is running. Kill anything that eats resources like crazy with the kill PID command. It has always been my go to methods on Linux systems. 
 
Don't know if it works for Android but worth a try.

I still have my 4790k and it works great with all games! I noticed its a little slower than it was in 2016 so I think im wearing it down a little. In your case I would probably wait a year or 2 before getting a new CPU. But switching to a new processor youll have to get a new motherboard, new DDR4 memory, and a new copy of Windows 10. A bit pricey unless you have the money

SLI is pretty bad tbh especially in gaming since most games have ditched it. 

Welcome!
 
I would just keep the single 1060 if you're just gaming, SLI is more or less dead.