YOU STUPID SON OF A....oh, wait. You said "no flames." Sorry.
"CCV" is the crankcase ventilation system. (Known as "PCV" on a gasoline engine, but it'll answer to either name.) It vents blowby gases from the crankcase. Look at the top of your engine. That round, black disc thingey with the little black hose coming out of it is the CCV fitting. Unlike a PCV Valve it isn't really a one-way "valve", though. Just a glorified plastic elbow fitting. Crankcase gases are routed into the air intake system upstream from the turbo, and eventually they are burned in the cylinders. PCV/CCV was probably the earliest "pollution control" system installed in cars, and was done to help prevent unburned hydrocarbons from escaping into the atmosphere and causing smog. It has absolutely NO ill effects on a car UNLESS you have an intercooler, like we do. The fuel and oil fumes in the CCV gases condense on the cool interior surfaces of your intake system, coating them with a thin layer of oil. That wouldn't be a problem, but that oil partially insulates the intercooler and reduces its efficiency. Airflow isn't restricted in any meaningful way, so it doesn't affect cruising fuel economy. But it does cut down your maximum power output under heavy boost a little bit. Routing the gases to the atmosphere is the simplest (and most illegal) way to prevent intercooler fouling. Some folks install some kind of filter on the end of their "elephant hose" in an effort to condense and capture the rouge oil and fuel. The most elaborate systems filter out the fumes and then return the gases to the stock fitting in the intake system, and the condensed liquids are captured in a sump of some kind. Drivebiwire has even rigged up a drain to automatically return the nicely distilled motor oil to his oil pan!
EGR means "Exhaust Gas Recirculation", and does exactly what the name implies. A portion of the exhaust is sucked back into the engine to be "re-burned." NOx (Nitrogen oxide) emissions are reduced because the effect of EGR is to reduce your engine's efficiency! Because some of the oxygen in the intake charge is replaced by nasty exhaust the fuel doesn't burn as efficiently as it should, and thus the engine produces less NOx. It does, however, make more soot, so you're really just trading one poison for another. The gub'mint has decided that soot is better than NOx, though, so we're kind of stuck with it.
The EGR valve is open whenever the intake air pressure is less than the exhaust backpressure at the EGR outlet, which means that it's open pretty much always except when there is a lot of turbo boost. EGR isn't particularly good for ANY engine, but it's especially evil on a diesel because the exhaust contains a high concentration of soot. (Relatively.) The soot combines with moisture inside the EGR valve housing and your intake manifold and will gradually plug them up. How quickly that happens depends on your driving habits, atmospheric conditions (especially humidity) and fuel quality. But sooner or later your intake will be clogged to the point that it will seriously affect engine operation. The solution will be to have the intake manifold pulled and cleaned out. You can easily keep an eye on the situation by pulling off the last rubber intake fitting just before the EGR valve housing and looking in the housing. Once the thing gets more than about 10% to 20% clogged it's time to fix it. (Unless you're Ric, who believes that the intake system is "50% overdesigned" and that the fact his TDI is sipping air through the equivalent of a swizzle stick isn't a problem.
) Anywhere from 50,000 miles to 150,000 miles will be the interval, depending on the factors described above.
If you could, in theory, ILLEGALLY disconnect your EGR valve your NOx emissions would increase by a factor of TEN! Your soot output, though, would decrease. Your fuel economy would improve slightly. Your intake would stay clean. Your oil wouldn't soot up as quickly because the blowby gases getting past the rings would be cleaner. All that internal cleanliness would mean that your engine would last a bit longer. And, if you get caught, you'd go directly to JAIL.
-mickey