There are: Static Addresses, Resolvable Addresses, and Random Addresses
Static Addresses always use the same number
Resolvable addresses are random numbers that resolve into a constant private number
Random addresses are completely random and have no association with the device
For privacy of users being tracked or monitored by their BLE address, iOS implements Resolvable addresses that are randomly generated, but can be turned into the private address of the device by trusted devices/services (and encryption of sorts). This allows only the devices with knowledge of the device's private numbers/calculations to be able to identify the device by it's address.
To answer your questions:
2. I believe it is too, yes.
3. This feature is only available for BLE v4.2 compatible devices (if you are using BLE v4.1, then it will be properly grayed out. Also, older psoc creator may not allow using it either)
4. Check that your chip supports BLE v4.2, PSoC Creator is the latest version, and the components in the project are updated to the latest.
5. There are APIs to call in order to add/remove devices from the whitelist, but the device will automatically filter devices by the whitelist if set to do so either in the BLE component, or in application code.