It's not clear?
There isn't any overclocking being done at all. The device is designed to operate at those speeds.
It might require some piracy for now, but the hax doesn't actually enable piracy by playing the downloaded games directly on your 3DS like that.
You could download a rom of whatever game you want and get the romfs file from it for rom hacks, but 2.5 won't allow you to play it unless you bought the game legally.
I understand that the n3ds has higher clock and the 2.5 hax enables that. But why did it stay downgraded?
Something else, can you tell me how to get romfs? Is it the xoprpads generated with cfw?