I for one don't see the issue with all these exploits. If you are complaining about them then you shouldn't use them. If you are spending lots of time finding out new exploits then it means that you want to use them and think of them as morally acceptable for you. If you think that exploits are fine use them; if not don't. Either way you are having fun and that's the point of the game.
Anyway reporting them could make people who like to use them unhappy, while those who don't like exploits shouldn't bother cause they don't like them and therefore don't use them in the first place.
It's been mentioned that game balance for EU4 is based primarily off of multiplayer.
And the reason why I think it's a bug, is that once your nation westernizes, an event fires that checks if you're Ming, and if you're Ming, factions get removed. If you're not Ming, you don't see it.
If the devs intended for Ming to get -75% Tech cost upon westernizing, don't you think that they'd have never created that event?