PPS is awesome! and i find the one on PICs to be more advanced and flexible than most other microcontrollers.
so, you have PERIPHERAL PPS input and PIN PPS Output.
this means that you can route only a single pin to a peripheral, but the same pin can become the input for many peripherals
this also means that you can route the output of a peripheral to different pins
Unfortunately there are restrictions in which ports can route which peripherals (i.e. CCP can only be on PORTB and PORTC) and a different package may have different ports for the same peripheral (i.e. PORTB/PORTC on 28pin, PORTB/PORTD on 48 pin) but in general you can always get the legacy mapping.
MCC is never necessary, at all. The mapping operation is damn simple and MCC is not a substitute for reading the datasheet anyway.
in the case of dsPIC, the datasheet clearly states in multiple places that in those parts the higher speed SPI can be achieved only on dedicated pins (it says that in the device summary tables, pps section, spi section, electrical specifications)