Will it also charge Power Delivery 2.0-supporting devices quickly?

Yes.
With the familiar USB-A, charging is 5V, 2.1A at the usual speed.
With USB-C, charging is optimised, up to 3A; I estimate that my iPhone X is charged in about 50-70% of the time.

Yes, it works quite normally. It also works with USB-C as long as you buy the additional cable from Apple. Then, depending on the device, even very quickly!