Always a good idea to replace fuel filters regularly (every 30,000 miles or 2 years) for many reasons. 1 A plugged filter is hard on the pump, 2 A plugged filter will deteriorate your MPG and performance, 3 A filter that stays on too long does not like to come off....rusts on.
As for your problem, I would definately clean the MAF sensor just because it is easy and free! Also fix your EVAP line leak <<< A MUST! Just for the simple reason that you know its a problem and you know it will hurt mileage.