Re: Scenario #1, my board and many other people's boards did this from day one. If it is a defect it is present on quite a few boards. There was no power spike when I initially received the board, and it is doing the same thing it did then.
Re: #2, yes there is most likely a compatibility issue. Different PSU was tried, different RAM, problem persisted through 2 video card upgrades and was there with a ~3W PCI video card attempt in the first place, and it is not the hard drive because board was pulled and retried with nothing connected but bare essentials.
I suspect the problem is the CPU, not bad but not truly supported but they claim it was supported a few bios releases ago and it is not isolated to people using only the same series of CPU plus anything worth running today would be newer, worth more than the board itself so I don't think it reasonable to make concessions around getting the board to work rather than using all parts known 100% working as they should.
From what I gathered at the time, about a year ago, the specific problem I and others saw was isolated to which CPU they were using. There may be other people with a general failure-to-post problem, certainly such a problem can have a lot of different causes, but only those with certain CPUs continued to have no resolution.
More than anything I was simply reporting that mine was also acting up again, and providing a point of info that switching to bios 18 may not only not be a solution but may leave someone unable to enter the bios menu at all so they should be prepared to reflash to a prior bios version if necessary. Mine is still running fine after having had to resuscitate it 3 days ago and not attempting to power cycle it ( I mean power cycle the PSU, system was able to shut off and turn on/POST by OS or case button fine, the problem was only if mains AC power cut out longer than the UPS could keep it supplied), so I'll leave it running while I contemplate what kind of upgrade that system gets (no rush, it's a secondary system I don't have to rely upon for anything crucial, and as mentioned it has ran flawlessly for roughly a year since the last time I had to fiddle with it).