new to the forum

Hi I,m new to the forum, I have recently bought a 2002 Renault laguna 1.8 16 v petrol model and have a few questions, why does the car rev so high in 5th gear it revs at 3000rpm approx, I had a starting fault which came down to the crankcase sensor, which is now sorted and why would i have at certain times have the battery charge fault light coming on, but not really on a long run, but the battery still seams to be charging. Thanks Paul