will running lower boost put less stress and heat on the motor making it last longer?

 

yes

 

it will also allow you to be eaten by b16 civics !

 

That goes for any engine. The more you try and get the maximum power out of any engine, the shorter you have made the life of that engine. I don't think it will lower temperatures the Rotaries are conventional ovens no matter what, for instance at idle. But even if you always baby your motor doesn't mean your engine wont blow even still, it myight blow up just because it feels like it.

 

Edit: Convection not Convention

I think Mazda figured this out and won't be offering any more 10 psi turbo rotaryies.

 

even at 7psi you will still smoke those foolio b16 honda clowns, trust me I know.

 

Stop trying to make a high performance engine non-high performance for sake of longevity. Build it right, beat it right and rebuild it right...