It's ok for home use and gaming imo, you can roll back if you don't like it.

Windows 10 is fine once you get used to it, and it's quite stable and secure. You shouldn't have any problems running most games, but a few of the very old games might have glitches if they don't have Windows 7+ compatibility patches.

Sure, but barely though.
Turn off and disable almost everything, get a few programms and you can make it look like win 98/XP and it will be fine.

unpin tiles
gpedit windows defender and onedrive to be off
turn off all privacy shit

happy day

all cool with win10

except patching updating hiccups 10240 version 2 10511 4 example
but thats just me and some for the most it runs and updates all fine

playing q3 QL DayZ Arma3 or UT and Reflex all work gr8

It is fine, but is loaded with a lot of bloatware, use PowerShell to get rid of them (if is microsoft's bloatware) and uncheck all the fancy animations.

Still, some games like midtown madness or worms armageddon need to be patched to play. W10 has a very shitty retro-compatibility.

i upgraded to Windows 10 in my Lumia phone, it is not bad but not that stable, there are bugs here and there and i heard a huge update is coming in August, so maybe it is worth the wait, otherwise you can roll back if you dont like it.