The very day windows 10 came out I decided to try to install it but, seen as the small icon on the bottom right corner didn't explicitly say "upgrade now" and rather would just open up a blank window that never loaded, I searched around to find a way to "force" the installation by using the command prompt and typing "wuauclt.exe/updatenow" 

This caused my computer (an ASUS G751J) to automatically download windows 10 through 'windows update', however, as it was taking too long, I stopped it right when it was already starting the 'installation' so I could try my luck the next day. When I tried to trigger the update again via the updatenow command, it did nothing at all. The next day I tried my luck again and same thing happened. 

Now, when I check the small windows icon on the bottom of the screen, it says "we're validating windows 10 for your pc, we recommend that you upgrade after you get your notification that windows 10 is ready for your specific pc". 

My question is, is anyone with ASUS computers having this same issue? Is it an issue even? Because now I tried the command again and windows update mentioned it was downloading and installing "windows 10" but right as it hits 100% nothing else happens, it doesn't even ask me to restart and no manual installation process goes on either.

Well great minds must think alike. I did more or less the same thing. The only difference is that after the download it asked me " we have a few questions to ask you before installation. ". Then it crashed. I found myself In the spot you describe. I decided to roll back the machine a day and wait for the upgrade to be offered. Yes, I do have an Asus MB.

If you don't want to wait, use this tutorial.......

How to Download a Windows 10 ISO File

http://www.tenforums.com/tutorials/9230-windows-10-iso-download.html

The tutorial actually derived from this Windows Blog:
http://www.microsoft.com/en-us/software-download/windows10

But, the tutorial is much better illustrated.

Follow the tutorial and create the ISO.

That done, right click at the ISO > click Mount > click Setup exe.
Installation will begin. It will allow you to keep your files, settings, and apps, or keep nothing.
This method does not ask for product key.

I used the above method to install my Windows 10 Pro. Automatic activation. No Problem.