About APU usage, it's not even so much the company or management making those kind of dumb decisions, it's airports... I mean, have a look at Amsterdam where you are not allowed to run the APU earlier then what, 10 or 5 minutes before scheduled off block unless temperature in the METAR is 25C+. Same kind of deal in Copenhagen.
I tend to just ignore these things and start when I feel it's needed, but am risking possible consequences like fines from the airport.