Run some SeaFoam through the system (or Lucas fuel injector cleaner). And definitely run it up to red line on highway on-ramps now and again. Helps to clean the carbon off.
BTW, I use all sorts of oils... LubriMoly, Valvoline, Castrol, etc. Sometimes I don't even use full synth when I plan on dropping the fluid again soon or doing an oil treatment... *gasp* (shorter oil changes when I don't obviously).
Use the full synth of your choosing in the recommended weights and you'll be fine. I'm sure there is reason for specifying a certain certification oil... but I'm guessing it's so that the dealer can suggest 10,000 mile+ service intervals.