yes
take off battery box air shoot air filter box in under that (drivers side of vehicle). undo line clips and replace filter.
first you must remove the air filter then the air filter box it is held on by 3 or 4 bolts after taking out air filter box you will be able to access the fuel filter
http://www.youtube.com/watch?v=GKhVXslh6Is
should be along the tubing where the air filter is. It normally has 2 wires connected to it
rigth below the air filter box
It is attached to the lower grill on the front bumper.
The Pollen filter is between the fan and the engine.
The fuel filter is located in a bracket bolted to the frame behind the right hand rear wheel. It can be seen with the wheel on but to repace it you will need to remove the wheel.
yes, it has an oil filter.
7.6 quarts according to the manual for a 2.3L 2005 Mazda 3. I can't imagine it's any different for a 2008 Mazda 3 with the same engine.
The 2008 Mazda MAZDA6 has a 3 yr./ 36000 mi. basic warranty.