Pressure compensated driplines start dripping once the line has reached a specific level of pressure. It will then irrigate at that pressure across the entire line regardless of factors like elevation. That's what makes them best for drip irrigation that occurs across hills or slopes to make sure both the crops at the top and bottom of said slopes get the same amount of water.

Non pressure compensated driplines on the other hand would give more water to the drippers at the bottom of the hill due to gravity, which can result in uneven distribution of water. However, these are fine to use on flat surfaces.

Yes, drip tape is a much thinner, lighter and cheaper version of dripline. Drip tape is used in short term periods while dripline is generally used for longer term periods. Drip tape is not as weather resistant as drip line. Lastly, drip tape suffers from not being pressure compensated, meaning it will be affected by elevation or slopes. This can result in the tape splitting from the pressure.

No! Dripline and Driptape both have specialised drippers built into them. If you puncture these, you will need to replace it. If you want to adjust certain parts of your irrigation to add drippers, sprayers or other sprinklers, consider joining it to a lateral pipe which can be punctured.