Subaru Repair: Noisy AC and fuel fliter change, independant shop, proper diagnosis

Question
I currently own a 2005 wrx sedan with no mods. I recently had the 30k mile maintenance done and the dealer had creditied the fuel filter charge on my bill. When asked he contended that the fuel filter on a 2005 wrx only needs to be changed when there is an issue with the fuel pump. I found this quite odd and see no mention of that in the owners manual. Is this correct?
 2ndly I have had my car in twice now for what I believe to be a AC compressor issue. Intermitedly when the compressor kicks on there is a loud hum/ vibration until the engine idle increases. The subaru dealer I take the car too has said this is "within specs" and that the system is working correctly. My brothers 2003 dosent seem to do this. Just recently at a stop light my girlfriend asked. " whats that noise?". The car is currently still under waranty and living in south florida it would be really hard to go without AC. Are there other things that I could check on other then the compressor. It only happens when the clutch engages. A/C blows cold. Thank you. I hope you can help

Answer
The guy is crazy you should replace the fuel filter regularly per your owners manual.  As for the AC compressor I would have to hear the noise to give a proper diagnosis.  I would take the car to an independant shop and get a second opinion on the compressor.  I have seen at times the system get air in it and it make a noise, a vacuum and recharge is needed to solve this problem.  I would honestly find a worthy shope other than the dealer you are going to, sounds like they might be a little lazy or dont know what they are doing!  Hope you get the problems fixed!