I'll try to be brief:
1. Good.... that 9.6.0.1014 driver may be the key to stability for you. Not likely that it will allow the M.2 Predator SSD to run cooler, but if so that is new news.
2. Yes, the chipset you refer to is the Intel 5520 In/Out Hub, and there was an earlier B3 version (sSpec code SLGMU) that was used in the earlier Z600/Z800 workstations which we call version 1, and then the later C2 version (sSpec code SLH3P) used in the later version 2 motherboards of these workstations. The boot block dates for the Z600 are 1/30/09 for the older motherboards and 1/7/10 for the newer ones. Yes, that 5520 chipset is located under that smaller heatsink/fan, the "chipset fan".
3. Do not worry so much about updating the BIOS. I have done that many many times using the safer method of updating it from within BIOS and also updating it from within the operating system. I have never, ever had a problem either way with the HP workstations. I prefer updating from within BIOS, however, and have posted on how to do that. For you I would recommend the other way because it is easier.
4. For me to email you my Replicated Setup cpqsetup.txt file you need to PM me inside of this forum your email address. A method to send private message to me is there via the links associated with my account.
5. The power needs of the M.2 drive is small, much under the 25 watts that the top PCIe slot provides. Hot Samsung m.2 SSDs under load draw about 5-6 watts. The Kingston datasheets shows the Predator runs at about 1.5 watts average, 2.0 watts maximum during read, and 8.3 watts maximum during write. You can put it there or in the lower PCIe x16 slot.... the top one is working fine, and a bit faster so I've put mine there. That is in the manual for the Z600.... it is slot 1, a PCIe2 -x8(4) slot. Which means it is a generation 2 PCIe slot and has a shape that is the standard x8 shape but can accept x1, x4, x8 and even x16 cards. It, however, has a maximum of 4 electrical lanes. Which is what you want.... Specifically do not use slot 3 because it is a slower PCIe Generation 1 slot. You want a Generation 2 slot. It is fine to use that lower PCIe x16 slot, but it is overkill, and a bit slower but is a PCIe Generation 2 slot and has more than 4 lanes. To get max speed out of the Predator you want to use at least a Generation 2 PCIe slot and have at least 4 electrical lanes available to it.
6. Kingston Europe is wrong...... I can see that if the correct storage driver is not used they would think so, but if you use the correct storage driver it is working great now on two Z600s I am experimenting on. It is fully stable for me, to the point that my main home office workstation is this Z600 running the Predator now for weeks on end with zero problems.