I do a backup every year, so will just have to do it 2 weeks before usual. I assume I can do this from safemode too.
A year?
On Win7 it's recommended you do a fresh reinstall yearly and updates way more than that (especially in this age with ransomware!)
Backups should be done as often as you feel you need.
My SSD from which windows is installed, it says 82% good.
My old HHD which I use for file says caution.
For some reason I assumed you only had a spinner.
SSD's need wear checks, they don't have sectors like a spinner. Yours says 82%, which means you've used 20% of it's lifespan, that's pretty heavy use, but unless it stars dropping I wouldn't worry just yet. If I remember right, this is based on the number of writes and wear leveling, so long as you have full capacity it should be okay. Reallocated sectors aren't the same as on a spinner as they aren't mechanical so if one gets worn out completely it won't lead to a cascade failure. I don't think they ever need scanning for bad sectors either, any scanning shortens the lifespan.
The spinner saying caution can be an issue depending on why.
Some S.M.A.R.T. readers have HORRIBLE layouts. I've seen them throw a warning simply because of age, imagine your check engine light coming on just to tell you that your car was old. Beware crappy interfaces too, I condemned a few drives thinking they were failing because it said "CAUTION AGE" and yet it was just the way they labelled it in the software was done poorly. It looked like they were failing due to age when it was just their way over amplifying the warning.
Spinners are like a car, they are more likely to have issues as they age (75% are dead after 4 years) but it may also still run completely fine for decades, age is important but it's only one factor.
As for the clocks, a bad memory overclock would likely turn up an error in memtest I would think.
There has been instances where a bad overclock that looked stable corrupted drive data though. I've seen it happen at least twice and while it was usually a driver issue that was later fixed the users still lost data. Unfortunately I don't remember if the error showed up in memtest.
Systems seam more safe and protected than ever but we also keep more and more of our lives on our computers, I've reached a point where I try not to do anything without a fresh backup because one oops and smoke goes flying. Trust nothing.