It looks like you did a great job building the CFC. I'm still planning on building mine but this is what I've been reading about the CFC cleaning/sanitation:
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Before using your counterflow chiller, give it a thorough cleaning to remove any dirt trapped inside the tubing. Pour a mixture of hot water and dishwashing detergent through the tubing (using a small tunnel) followed by a hot water rinse. Repeat until the rinse water is clear and clean. Sanitizing your chiller is easy. After each use, simply run a few quarts of boiling water through it, straight into the drain, without any cooling water going through the hose. That flushes out trapped droplets of wort, sanitizing the entire length. Next time you use it, don’t turn on the cooling water until you let a cup or two of boiling wort run through the chiller into a bucket or drain (not a glass carboy!) Stop the flow and throw away the first bit of wort. Then turn on the cooling water and start collecting your cooled wort normally.
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To sanitize the device, a sanitizing agent must be run through the inner copper tube for 10 or 15 minutes prior to use, then the agent must be thoroughly flushed with water. After being used, it should again immediately be flushed for
5 minutes with really hot water. Of course, since it is the inside of the inner copper tube which comes in contact with the wort, one never really knows if the chiller is clean. There could be all kinds of gunk inside that tube, and we'd never know about it. This is why the brewer must be absolutely meticulous when cleaning and using a CF chiller. There is absolutely no room for laziness or poor sanitation habits. Probably the most effective way to ensure proper sanitation of a counterflow chiller is to use Powdered Brewers Wash, details of which can be found on our sanitation page. This product is designed specifically for clean-in-place applications in the brewing industry, where you cannot see the surfaces you are cleaning. It is extremely effective at removing the organic compounds left behind by beer and beer wort. Another good cleaner to use here is OxyClean. Both of them need to be extremely well rinsed, and afterwards the chiller needs to be sanitized with a sanitizing solution. If you have a pump, an effective way to sanitize a counterflow chiller is to circulate 170F+ water through it from the hot liquor tank for 5 or 10 minutes.
As far as copper oxidation; the majority of our water pipes here are made up of copper. I haven't heard of any problems with is.
Hope that helps.
Wild