Nice. I used the same wine cooler for fermentation chamber for a while, but converted it to a kegerator and ferment in a full size upright now .The temp display is nice, it's a pretty accurate reading, and will read well below the fridges set point if you use an external controller.
Sounds like a good idea.
I was doing some triclover to camlock fittings recently also and was about to do the same thing when I found and opted for the following:
https://www.brewhardware.com/product_p/camtc15.htm
As clean and sanitary as you can get a threaded fitting, I don't think you can...
Correct.
+2°C is +35°F, however the difference is not the same, that takes into account different values for freezing point.
2-3°C difference is about 3.6-5.4°F.