You can do all that your self. Spark plugs are easy to do. Don't buy them from the dealer. My dealer wanted $16/plug. Multiply that by 12 for the V6 engine...well. I got mine online for ~$5 ea. I have seen post about people having trouble with Bosch Platinum +2 and +4. Might want to stay clear of these. Air filter is very simple. Fuel filter is a bit more complicated but is still a DIY job. There are previous post on how to do everything you are asking. Just use the search. You could also get an alldatadiy subscription, about $25/year. well worth it.
All Dealers want you to think that taking your car somewhere else, or doing your own maintaince will void the warranty, but if you use OEM recomended parts and use them properly no warranty will be voided.
All Dealers want you to think that taking your car somewhere else, or doing your own maintaince will void the warranty, but if you use OEM recomended parts and use them properly no warranty will be voided.