Major issue with very slow opening/freezing file loading

So - i've been experiencing various issues since using this laptop. I had the screen replaced due to a dead pixel about 2 weeks into using it. 

Currently, I am running into a few strange problems (I'll list based on varying levels of trouble):

1. File opening length - this is a really mad one. If I go to downloads, or even files in desktop folders, the laptop just goes into 'spinning circle mode' and will take AGES to do anything. Like selecting 3-4 files to delete from Downloads folder even causes this issue.

The computer otherwise works super quick. No issues opening webpages etc, but this is obviously extremely problematic. I ran a diagnostic and it says all is working fine on the laptop, but I often have video files/AI files I need to open...and waiting 1/2 mins for a file to open is crazy. 

2. Problems with hibernation - a real problem: when I put the computer into sleep, i brought it out from its case later that night/next day and the laptop was ON FIRE (like, almost unbearable to touch) and battery critically low. 

After reading some online forums about Windows I have opened and activated 'hibernate' mode, which seems to be working better. However, having the ability to shut and go is something I'd like to have back

3. Webcam - i've read a good bit online about this being pretty useless, but when I start mine it's fuzzy/colours are off, and looks worse than my Dell XPS 13 from 2.5 years ago. Surely it's not a cheaper tech in a more expensive laptop...surely?

Appreciate your time all, and hope to give back to the community here.