[jakobnev]

why do you think heating the air will make the turbine extract more energy in this case?

Heating the air increases the volume that passes through the turbine.

And of course there are enumerable energy conversions going on as well with losses, from the throttle plate pumping losses

What throttle plate pumping losses?

I don't see how it could stack up to eliminating those losses (i.e. direct injection or pulse and glide).

Unless you are talking about diesels i don't see how direct injection eliminates throttle losses.
I't hard to predict how it does against P&G because while P&G eliminates throttle losses it doesn't do anything to convert the heat in the exhausts to useful work either.