I'll try to answer your questions to the best of my ability, let me know if there's something you don't understand or want me to go over again.
1. I was not given a windows 8 key when I received a laptop. i heard that with new laptops windows keys are embedded into motherboard or something so even if my windows gets corrupt, i would have to simply run the setup and it would not ask me for a key. Is it right or not?
This is right. Now a day, the product key for Windows is embedded in the BIOS, and during the installation or activation phase, Windows should be able to grab the product key from the BIOS and use it to activate itself. If it can't find it automatically, you can try to find it and enter manually. The link below contains a tutorial showing you how to proceed.http://www.nextofwin...-key-from-bios/
2. If above statement was tight, would I be able to upgrade free of cost to windows 8.1 again or not?
You can upgrade from Windows 8 to Windows 8.1 free of cost via the Windows Store. You just need to make sure that all your Important Updates (Windows Updates) are installed first since a few of them are prerequisites. Once done, upgrading to Windows 8.1 will be the first thing they'll propose you in the store once you go in it under Windows 8.
3. Again considering that my laptop price included the price for windows, am i allowed to download a setup of windows 8 from somewhere and make a bootable usb off of it and use it to install the windows on SSD? If yes, can I have a good link for the windows setup?
Microsoft provides two installers, one for Windows 8 and the other for Windows 8.1 in free download in the link below.http://windows.micro...roduct-key-only
You need to enter your product key to be able to use the installer. Once entered, it'll offer you the option to create a bootable installation media on a CD/DVD or USB. Your Windows 8 product key will work for Windows 8.1, so you could use the Windows 8.1 installer right away, prepare the installation media and proceed to install it. The only thing I'm un-sure is if a OEM Product Key like yours will work with these installers (if it'll be accepted or not). You'll have to try in order to know. Otherwise, using a generic product key for Windows 8.1 could work, and then you'll just activate it on your new installation.
Hopefully this answers your questions