I see favorites adn PoI as the same thing but in a different category.
PoI categories could as an example be
Favorite (as in personal only for myself and to be shared between MRA and my own GPS),
Friends (my favorites visible for my MRA friends)
MRA (visible to all MRA users
external (lists of PoI coming from i don't know where)
For the rest they could be identical. That would also allow to simplify the user interface of MRA