Your motherboard can split the x16 from the CPU into two x8 slots (two slots! not x8/x8 in one). That's the full extent of its bifurcation abilities (bifurcation requires extra hardware, it's not just a firmware thing). So you can add two m2-pcie cards using two passive adapters in two slots...
In olden times the HD light was driven by a disk controller. Some M2-PCIe adapter cards have pins for connecting the case LED. Otherwise it's entirely up to the motherboard to generate it (or not).
Depending on how strict with terms you want to be...340x0 cards could be used for 3D acceleration. Since they were full fledged CPUs, they could do 3D even if lacking dedicated 3D functions.
It's a shame that the optical audio port has never been updated. It's stuck in the year 1982 forever. But still beautiful because of the electrical isolation.
Though the specific results vary between models, in general SSDs work better when they are not anywhere close to full. This is even true for "enterprise" SSDs.
"64 bit only" refers to OS...x86-S still runs 32-bit code. The only thing you might miss is the ability to boot up in classic BIOS mode, run MS-DOS, etc. Not an every day necessity but can be useful.
I suggest the low tech approach...no RAID, install two drives, use the other two as external USB backup drives. Periodically connect and refresh the backup drives.
Memory is a boom and bust business. There are only 3 major DRAM manufactuers left (and I guess about 5 flash manufacturers?). They will all survive and be just fine. Enjoy the low prices.
You linked to a completely unrelated product, it's not even a laptop.
Give the memory a try.
Is this it?
https://web.archive.org/web/20210603232644/http://h10032.www1.hp.com/ctg/Manual/c06248869.pdf
This part was surprising to me - it turns out you can bypass all that stuff simply by writing an "off" code to the registry. You would think it would be harder!