I remember hearing someone say the additional watches were compasses or something similar for artillery, but its been too long for me to remember anything about where I heard it.

This looks like a more hardware focused job listing, so if you have a typical CS background you probably lack some of the expected skills for it. Note the mentions of RTOS, embedded, hardware schematics/bring up, and ARM core knowledge.

What happened to PPB? I haven't seen it in a while despite a ton of PPB worthy posts

I wonder if largest meant "most people in a building"?

The trick with the economics of nuclear is that building it is the main cost, once the plant is operable the cost is much lower than other sources. So by the time you have a working plant, you might as well use it to get value out of it since you have already paid for it.

Did anyone else feel like the second Act of threads was a lot weaker than the first?

Java/C# would have types before the variables:

double sum = 0d;
for (int i = 0; i < 4; i++)
	sum += 3 * i;