A new motherboard and a new screen! I'll bet you anything it was a loose (maybe just dodgy) data ribbon that goes from the screen to the motherboard. I would be highly suspect that the screen and the motherboard failed at the same time. I hope you're not paying for any of this.
Yes, I added a SSD to my HP, no issue, and hell yes faster. did a clean install of Windows 10 witht the Original Windows 10, and it auto installed Professional... was never ask for a KEY and never entered. it just auto install Pro and Activated.... boot to USB and run /apply from Command prompt. took about 15 min all together.
You may also want to buy a kit that will upgrade you to 8.1 Pro from Newegg or Amazon which would allow you to upgrade to Windows 10 Pro, anyway glad you are getting your laptop back, good luck.
Forgot the battery life. The changes are negligible. But the SSD, well... is best single upgrade I've seen since the AD 1982. It can literally resurrect any PC sold since the beginning of the millenium. Do the upgrade blindly and w/o thinking,, especially now that the prices are really cheap, you'll never regret.
There is NO need to buy a kit to clean install Windows 10 on any Windows 8, MS said as long as you DL the ISO it will work, and indeed it does, every Windows 7, Windows 8 laptop and desktop I have been able to CLEAN install Windows 10 and every one came with Windows 10 Pro. and activate usually with no more than 3 reboots. most we on the 2nd Reboot... and if needed use the Generic Key that MS gave to insiders. for Activation