Best Steps To Preserve Engine/Fuel System?

Normally, I just run some B-12 Chemtool (similar product is Seafoam) in the tank every 10,000 miles. This should clean the fuel system of any deposits (including injectors) and even clean the inside of the cylinders to some degree.

Is there anything else that should be done with a Prius to ensure the ICE is in tip-top condition for as long as possible so repairs (like injector replacement) is never needed (or not needed for a long time)? I'm guessing the high rate of issues (compared to other vehicles which I never hear of this problem) comes from the ICE only running occasionally and perhaps never getting as "hot" as a traditional ICE (which helps burn off junk and blow it out the exhaust).