Re: iPad charging plug
If you are using the iPad while charging, it will get warm, but not dangerously so. All iPad chargers tend to heat up while charging, so unless it is warm to the point of worrying that it will catch on fire, I wouldn't worry. If it does concern you that much, I'd take it to an Apple Store and have them look at it for you.
Keep in mind that if the charger is third-party, Apple will not help you. Some third-party chargers have been known to catch fire or push too much power to the device, so Apple doesn't support them. If it is an official Apple charger, they should be able to help you with it.