Yes.
That depends on your parents and local law enforcement.
to many deaths from the use of them
Yes it does and it will eventually destroy the seals. Never use and oil on an airgun always use Crosman Pellgun or RWS oil they are designed for airgun seals.
No: usually you must be over 18.
It's up to your parent's, but you must be 18 to purchase one.
Only if the airgun has a scope rail designed into the gun. You will also need an airgun scope not a firearms scope.
You can't it's not designed to be a repeater.
The highest velocity of an airgun is that of Evanix AR6 pistol which is 1000 fps.
If you mean to purchase Airgun's and airgun accessories, I think Airgun depot has great prices and fast shipping. Pyramid Air is very good as well I hear.
depends on where rats are. If in your house i recommend old school spring traps. if in shed i recommend getting airgun
I clean my rifles around every 500 pellets or sooner if I think they need it. I do have some suggestions for cleaning. First of all never use regular gun cleaning products. the cleaning agents will damage the seals in the airgun. Only use Crosman pellgun oil or RWS airgun oil to clean and oil the airgun. You can purchase cleaning pellets from "pyramyd air, See Link Below" to clean out the barrel or purchase a airgun cleaning kit. Add a few drops of airgun oil to the working parts of your rifle. Put a small thin sponge in the bottom of your pellet tin with a little pellgun oil to lubricate the pellets, This will coat your barrel on the inside. Don't over oil the air rifle.