help : update manager : level 5 updates (linux firmware and linux kernel)
 

Phoronix or tomshardware are usually good places to see reviews. Seems like 4.10 is the level to be at - I'd doubt that is even in the Mint lists, but haven't checked.
FWIW I just removed the level 5 stuff from Mint in this house - not my machine, caused too many questions. I use Fedora running Linus rc kernels so I can keep an eye on latest developments.

I personally don't have a problem with level 5 updates (my mintupdate preferences are set to show these but not auto-check them as I like to see what's going through the pipe).

The thing to remember is that these levels are a Mint invention. If you run the normal sudo apt-get update, sudo apt-get upgrade combination on the command line, it knows nothing of these levels. The levels are meant to protect more naive users who wouldn't, for example, know how to roll back the kernel or know what do if faced with a before/after configuration file question during installation.

The key, and this should apply no matter your system, is to take fairly regular images or backups of your system. Then, if anything goes mega awry, you can roll back to a previous installation state. Generally, if you have to reinstall your system then you haven't been doing things right (although admittedly a reinstall is a good idea from time to time, say every couple of years when a new major version of the distro comes out, in order to clean up some of the crud that's accumulated).

In summary, level 5 updates are safe if you're protected by having backups and you have the knowledge of how to roll back a kernel version if required.

good advice - suggest how to implement
 

This sounds like good advice to me. But it raises a few practical questions.

First, since I just built new Ryzen 1800X systems to replace my hardware/firmware/software development systems, the new kernels are important to me (since Ryzen support and bug-fixes are coming hot and heavy now that Ryzen is out in the wild). But when I installed them, my system would crash then "fallback' (whatever that means)... or not even boot with one set of kernel files.

And no, I don't know how to roll them back. Can you tell me how to do that, or link to a "rollback for dummies" article?

Also, can you suggest how to create images? I used to do that regularly on Windoze with a software application that actually worked for me (and made some sense to me), but every Linux back application I read about just left me so totally confused I was more afraid to try it than not. As a hint to help you give me the best advice for me, I'm someone who doesn't trust "fancy". And so, I always did "complete images" with no "incremental" or other tricky business (and so, naturally, all restores were full restores). When I partition my disk (or lately, SSD) when I install Linux, I try to simplify this process a bit by creating the following four primary partitions: "/boot" (1GB), "swap" (32GB), "/" (32GB), "/home" (~180GB to ~420GB depending on SSD size). Which MIGHT mean (you tell me) it is reasonable to save and restore just "/boot" and/or "/"... or "/home" (assuming that doesn't cause Linux to freak out somehow, due to info in one partition that gets outta sync with what is in other (just restored) partitions).

Also, if level 5 is supposed to be [fairly] safe... why have I gotten crashes and failure to boot every time I installed them?

Do you see a Grub boot menu when you boot your machine, if even for a very short period of time (if not, see https://forums.linuxmint.com/viewtopic.php?t=55370)? The entries on that menu allow you to choose to boot from an installed kernel other than the one that is the default (normally the latest installed). Once booted, you can remove the non-working kernel using View->Linux kernels in mintupdate (and then ensure you don't choose to install it again, skipping until the next kernel version hits the repository).

I come originally from the world of Windows too. I still use a Macrium Reflect bootable USB stick (actually on a YUMI multiboot stick) to image my partitions to an external hard drive because I'm used to it and it works a treat. However you do need Windows in order to install Macrium Reflect and initially generate that bootable ISO (I use my VirtualBox Windows VM on Linux Mint to do so). The most quoted Linux alternative is CloneZilla Live.

I image /, /home and /home/data (a creation of mine as I like to keep the personal configuration directories and documents/data directories separate) - if I've ever had what appears to be a pretty fundamental system problem then I've restored the first two of these partitions (for exactly the reason you cite, to keep things in sync). I've never had to restore the data partition (but incidentally I also incrementally mirror the files in /home/data from time to time to an external hard drive using FreeFileSync on a file-by-file basis, and sometimes I've had need to drag a file or two back from there if for example I've made an error in editing a document and saved it).

I can't answer your final question I'm afraid, but it certainly doesn't sound normal. Perhaps you should start a new thread in the Hardware section, citing a particular occasion that arises, to see if anyone has any ideas. It could well be Ryzen-related.

I'm still trying to figure out how to make new kernels work on my new computers to improve support for my Ryzen CPUs.

I'm still trying to decide what software is best to create (and re-install) partition images.

So... a few more questions:

#1: Is it likely the reason new kernels crash is because the nvidia drivers are matched to the previous kernel? So far I have not been pushing my nvidia drivers past the newest version suggested by linux mint (which is 375.39 if memory serves). But I sorta half remember they may be "matched" to the kernel somehow. Which makes me wonder... do I need to reinstall them for the new kernel? But if the new kernel always crashes on startup, how can I even do that (since it presumably "falls back" to a previous kernel)?

#2: What partitions do I need to back-up to "undo" a crash of a newly installed kernel? Just "/boot"? Just "root" AKA "/"? Both of them? Am I correct to assume that "/home" doesn't really need to "stay in sync" with "/boot" and "/" partitions, and thus can be backed-up and restored independently (if and when specific reasons arise)?

#3: I just built multiple new Ryzen systems with 100% identical components (except for the moment one has GTX680 GPU and the other has a GTX580 GPU, which from past experience both run with identical drivers). So does that mean that when I get one of them working, and make a backup image of "/boot" and/or "/" [and "/home"], I can restore those partitions onto the OTHER identical systems as a way to install the latest-and-greatest? I understand this doesn't work unless I have exactly the same CPU, motherboard and other components in the system, but with the minor exception of the GPU, that is exactly the case.

PS: If there is a really good [and thorough] article somewhere about installing [and removing] new kernels on Mint v18.01 (or in general), I'd love a link to that.

Thanks!

#1 - No idea. Perhaps you could ask that in a new thread.

#2 - You don't need backup images to roll back from an malfunctioning new kernel to a previously functional kernel, you just use the Grub menu options to do that (see the first paragraph in my earlier answer).

#2 - As per my earlier answer, I tend to restore / and /home at the same time, although it's not really necessary. You should be fine treating them independently.

#3 - I imagine that you would be fine with the same image. That's how some folk install operating systems on many computers with identical hardware.

PS - Have a look around to see if you could find such an article (have a look for Ubuntu as well as there is much common ground). I merely install new kernels when they are suggested by mintupdate or apt-get upgrade, and always keep three generations of kernel available by deleting older ones through mintupdate. It's Mint 18.1 by the way, not Mint 18.10.