I've always gone by the adage of "if it's not broke, don't fix it", but that doesn't stop me from wondering.
And for the most part, especially with BIOS updates, that is my philosophy too. And nothing wrong with wondering, or checking it out.
The first update you mentioned illustrates the typical update - support for newly released CPUs, not a problem unless you are getting one of the new CPUs. With the second update though, I agree, "modify CPU code" is not very helpful. I have seen similar descriptions that amounted to nothing significant for the masses, and similar descriptions that suggested the modified code improved CPU stability.
For drivers, which I include the BIOS, I generally recommend updating only in very limited circumstances. (1) The update addresses a problem I am currently having, (2) the update addresses a security problem (rare), (3) the update is needed to fix a corrupt BIOS (very rare), or (4) the update adds support for new hardware I will be using.
It is EXTREMEMLY rare for a driver (including the BIOS) to suddenly go bad (without something obviously catastrophic happening). So if these minor problems you are having are new, not something you have been experiencing all along, I would want to make sure I could not attribute the problems to something else.
That said, flashing the BIOS, while still risky, is much safer than in years past. And most of the major motherboard makers have user-friendly Windows based update tools to make it easy and safe too (so you don't have to create a bootable floppy or CD with the update). Most of these tools also provide a means of creating a backup of your current BIOS, so you can roll-back, should the update fail. Something I urge everyone do.
If this were me, I would make sure Windows is fully updated, the computer is clean of malware, heat is well managed, then give the update a go -
weather permitting. And I mean that. Even though updating the BIOS is much safer today, a sudden power outage during the middle of a flash update can turn a motherboard into a brick.