Aerator is the little metal screen that is threaded on the end of each faucet, it doesn't take much to plug up those screens, and when they do, water flow sucks. Just unthread it and soak it in some CLR or something.
Unless your hot water tank is starting to pinhole, you should be just fine with dropping a new element in it. When you pull the old one, you can get a lot of the hard water deposits out of it at the same time. Just a word of advice, turn off the breaker Yourself! Don't send a neanderthal cousin to shut off the breaker for you, because he'll shut off one nowhere near that breaker (when they were all labeled)....ZAP, nothing quite like being nailed by 220V :oops:
