Unless you are running ethanol free premium and have calibrated your wideband as such, stop looking at AFR. Log and think about all of this in Lambda. Stoich for any fuel will always be lambda = 1. AFR will change depending on what mixture of ethanol is in the fuel, but the computer is changing fueling based on lambda. The LTFT and STFT are percentages of error from Lambda.So that screen shot shows the afr at 14.18 all the way across except at wot. That's not right is it?
PE will not really there to add any power. It's there to protect the engine under heavy loads. If you are doing short duration stuff with lighter loads, like drag race cars, you might want PE in the lower range... like 1.10-1.12 lambda to maximize power while sacrificing some safety. 1.20 is usually where heavy, long duration load guys live in order to maximize engine protection at the loss of a little bit of power. The extra fuel helps keep everything cool and keeps you from melting pistons and valves.