First, it's not causing you any problems and hasn't even been seen for a while (in almost a month). Leave it alone.
Windows collects data and labels it a Warning or an Error depending on collection criteria - which isn't necessarily related to it causing problems for you.
As for running SFC (system file checker), there's no need - but it wouldn't hurt if you did it.
But then you'd possibly open yourself up to a whole new bunch of errors.
Again, as it's not currently spitting errors into event viewer and it's not causing you any problems - leave it alone.
As for hardware problems, what sort of hardware causes an error and then stops for almost a month?
I have seen nothing to indicate that it might be a hardware problem.
3rd party programs is a term used to refer to non-Windows programs. It gets a bit confusing when talking about Microsoft mouse and keyboard hardware - but the point is that it's a program that the Windows folks didn't include in the distribution of the OS. Things like Skype and hardware updates through Windows Update confuse it even more - but most of the 3rd party programs are just programs that didn't come with Windows.
So, yes, that means VLC and Firefox
The chances that svchost.exe and ntdll.dll are damaged isn't likely. As they are core Windows files, I'd expect many more problems if they were damaged.
Additionally, WIndows has many methods to protect and repair these files - so again, it's unlikely.
Finally, you can "repair" them in several ways (replacing it directly, using sfc.exe, or doing a repair install) - but as this isn't causing you problems - leave it alone.
Q1 - Event viewer is a very complicated tool. In most cases you don't need to even look at it unless you're experiencing problems. As you learn more about how Windows Internals work, you may delve into it. As for me, I use it primarily to look for problems - after someone has reported problems with their computer. The only time I look at my own Event Viewer is either to cite examples, or if I'm having an issue.
Q2 - Yes, it is unrealistic to expect to see 0 errors and warnings in the Application/System/Admin log files. I've never seen a system without them (unless the owner has turned the reporting mechanism off) - and I've been doing this intensively for many years.
Q3 - I can't tell you how many you have unless you zip up and upload the Admin log file for me to have a look at. But 926 isn't very many. Mine (I'm running Windows 10) has 709 over the last week (I must've cleared it out back then). FYI - the Admin log is just a collection of different reports - it's not meant to be a complete reference. For that you'll have to look at the Windows logs (and others). The most common ones that we use hare are the Application and System log files.
Q4 - I'm not up to speed on kernelbase.dll. It's the Windows NT BASE API Client DLL In short, it's another core component of Windows.
As such, it's protected by the different mechanisms I discussed in the paragraph just before Q1.
Also, as it's not likely that these are the actual cause, that's where we start suspecting the 3rd party programs.
For that I sometimes use the Admin log to see if I can spot a pattern of errors (such as another error that always comes before the kernelbase.dll error).
Here's an example scenario from my BSOD research. Remember that I'm a kernel specialist, so this'll be from that perspective (in other words, rules may be a bit different for user mode stuff).
Suppose a 3rd party driver writes to a memory address owned by a Windows driver.
Nothing may happen for a while if the Windows driver doesn't look at that memory address.
In the meantime the 3rd party driver can exit and we're left with no evidence of it.
Then, eventually, the Windows driver looks into the memory address that the 3rd party driver wrote to.
It doesn't see what it expects to see there - and it panics!
And when it panics, it quickly crashes in order to preserve the system.
At this point we're called in and we try to reconstruct things in order to find out what happened.
But the 3rd party program had already exited - so our job is made much, much harder