All your drip distribution lines, emitters, and microsprays are essentially freeze proof. However, you do need to freeze protect your system components, that is the filter, pressure regulator, valves, etc. For common faucet mount systems those items are most simply disconnected and taken indoors for the winter.
Actually, no. But people frequently do bury most or all their drip lines, either for aesthetic purposes so they are concealed or so the lines are not a trip/fall hazard. Tubing can be concealed under mulch or decorative ground cover or simply buried a couple inches under the ground.
Virtually all our components will work with any brand of drip irrigation systems. Tubing is sometimes an issue because it there are many slight size variations from brand to brand. We carry various fittings than can mate up to any tubing. It is usually best to bring in a small sample of your tubing.
Our commercial irrigation grade tubing is extremely UV resistant and is warranted for seven years. Our experience is that even in full sun at Santa Fe's high elevation, the real life span is 20+ years.
The dense molecular structure of the polymers used makes the components very smooth internally so calcium buildup is not an issue. A more common problem is other particulates and solids in the water supply. That's why a good quality filter is essential. And don't forget to clean and/or replace the filter screen regularly.