As a long-time Dialga player, I'd argue Metang as acceleration with Dialga as the main attacker is better because if you whiff a key turn you can come back later.
What are you talking about? That card is NOT balanced. Dangerous Laser is going to break the format, 60 Dangerous Lasers is going to be the new BDIF!
Source: My uncle is pikachu
The other players don't know that you are cheating, do they? And if they keep going to the store without complaint, it shouldn't be their fault that one player thinks they're better than everyone else and deserves special treatment.
You have still justified it in your mind. Just don't go if the store is scamming you, but don't cheat the other players. Not doing it every time doesn't make it better, and you have already done it 5 times. Just don't cheat.