Feather,
When taking off with packs being supplied by APU, there is no correct response (using KA sops) to the before takeoff checklist and more importantly there is no reminder that you may have the incorrect configuration. How would you respond to the checklist if the APU was supplying the packs?
“Who cares whether they are fed from Eng or APU!” You should care, especially if your RTOW was calculated on improved climb. Forgetting to select APU bleed to on will void your calculations.
Regarding brakes, the FCOM 3 clearly states “ . . . .and high temperatures”. It is becoming common practice for guys to switch them on 5 minutes after every landing regardless of temp or ECAM master caution.
I always giggle when folks switch the fans on when the aircraft will be terminating overnight.