Harlon

i am pretty sure that it would all work (as long as your CPU has integrated graphics). It would take some strain off of your GPU. i have 3 monitors connected to my monitor and if my CPU had integrated i would use it. with the mouse situation, i would just test it as moving one cable up would destroy or mess up any of type hardware so just test it but you would gain small amount of fps.

I'm not a professional but dealt with this last week to recover a drive labeled defective by a repair shop.  Here is what worked for me. I can also help you make a bootable disk if you need.
 
1. Turn on the PC without the drive and get into your BIOS to change the boot order and maybe make the current boot drive the only option.
2. Shut down and and insert problematic drive. If this works you're good!
3. If not working, insert a windows bootable USB after adding USB boot drive to the boot order as you did with the drive in step 1
4. In windows boot drives there is a repair option. In that option you will find an option called troubleshooting I believe.
5. In that option select command prompt. 
6. When in command prompt type "diskpart". This is a software on windows computers to view and modify drives within the command line.
7. After beginning diskpart, type "list disk" to view disks.
8. Identify the problematic drive and type "select drive X" with X being the drive number. (MAKE SURE YOU KNOW 100% IT IS THE RIGHT DRIVE. YOU WILL BE WIPING IT.
9. Once the correct drive is selected, type "clean" and the disk will be fully wiped for your sake. 
10. Shut down your pc and remove the bootable disk. 
11. If you removed your boot drive from the boot order in the BIOS, re enter it.
12. Boot into windows and hit "Windows Key + R and type "diskmgmt.msc"
13. Once inside, find your drive, right click and "Create New Volume". You will go through the process of formatting and the drive will be visible and usable.
 
Again this is what worked for ME. I hope it works for you! If not, I hope it was of some assistance. If not, then RIP my 5 minutes writing this lol.
 

Sorry. I should have worded it better. I am looking to buy that monitor off eBay for cheap but it has a broken screen so I am looking if I can find a replacement so that I can use the monitor like normal.

I think that you should save a bit more and get a Ryzen 5 3600 which will last you a long time, be able to play games and you can video edit fine. The gpu is respectable. I have a 1060 and a 3600 and I can do all of what you want to do to a good standard.

Thank you.

I think that maybe you could spend an extra buck and get a 1660 super for around £229 which I don’t know what is in your currency. If you wanted to spend even more you could get a 2060 which is a better card but at a higher price going for £300

Only when you ask, your chance of it happening becomes possible.
 
The discouragement from people for them asking is quite disappointing. I think there is no harm in putting the word out that they are interested in this, because if they never ask, they will never know if they could have or not.