only reason I didn't last fans is because it shoulda been common sense
as far as two pumps go, yeah they add heat to the water, but it works, DEPENDING on the situation of course....which his really wouldn't merit it's use. It'd only be somewhat beneficial if you were running parallel loops and had your GPU and CPU blocks seperated with one of those two pumps for each but then that'd also require a seperate rad.
PCB mod I'm assuming he's talking about voltage mods specifically. Cutting traces, soldering wires, etc...things like that on the motherboard to add voltage to things like the chipset, memory slots stuff like that. 1337 = leet in 'leet speak', that's not really worth knowing