How do I check to see if I'm shorting it out on the wall of my RDA? And what's an RDA
We're assuming you're using a rebuildable dripper (RDA). That's a type of atty. If you're using that, or a rebuildable tank, you should measure it with an ohm meter, or a digital multimeter to make sure that the coils are not shorting out. Prebuilt coils can short, too, so multimeters/ohms meters are useful to have on hand.
So, what are you using as a topper? What resistance?
Take apart the mod. Clean the entire thing. idk what the pins on your mod are made of, but clean them, too. Put everything back together. Tighten everything.
Make sure that your bottom pin is rising enough to make contact with your battery when you press the button.
Make sure that the top pin is making contact with your atty.
Make sure there's no battery rattle.
EDIT: Also, when you say the plating is coming off the pin, you mean the pin on the mod, right? Anyhow, I think that's a bit odd; I don't know what they could have plated over to get that to happen. Usually, they'll have silver or copper plated brass pins, or just solid brass pins or copper pins.
Solid copper pins will in time turn blackish with oxidation. That needs to be cleaned, as it'll cause voltage drop, could even keep the mod from firing. Brass pins take way longer to get to that point.