- Breeding (Not negotiable, just talk)
I don't think Breeding can't be a feature in PRO.
Decrease chance to catch a special pokemon. Increase time to breeding.
Breeding pokemon competions? Player can get only 1 legend pokemons in each competition and they can't trade these pokemons, breeding pokemon from competitions and catch another before they released that. They can trade after competitions finished.
And breeding good pokemon? I think player can't trade breeding pokemon or trade only 1-2 times.
In my opinion, limit in trade will help you in this problem.