Of course on my Linux laptop Chrome wouldn’t update automatically either through the browser or from the command line
Can you be more specific? What are you running on the command line and what is the result? Normally, you would install Chrome via a package manager, and that package manager would be responsible for updating it.
Yes, this is normal and it’s a good thing (unless you’ve come across a bug). I don’t know exactly what app the screenshot is showing, but I’m guessing that the caching shown is referring to the filesystem cache. The kernel is keeping a cache of files you are likely to access again so that it doesn’t have to read them from storage again. So what you’re seeing here is that some memory contents were moved to swap to make room for filesystem cache. This is because the kernel believes you’re more likely to access those files again rather than the memory contents. If it’s right, then this a performance improvement despite the fear surrounding swap usage.
Setting a low non-zero swappiness value is telling the kernel that memory contents have priority over filesystem cache for remaining in RAM, or conversely that file cache is more likely to be evicted from the RAM. A value of 100 would mean that they have equal priority. So that memory content must have been very stale to be evicted despite having a significantly higher priority to reside in RAM.
So:
Source: https://chrisdown.name/2018/01/02/in-defence-of-swap.html