4. APU procedure is to put APU on busses and wait for 1 minute before using as a bleed source - understand that fine, but what if we are on stand for 30mins in a hot destination and just want to use for A/C with ground power connected? Is there anything stopping using APU for bleed air but not electricity - I would assume it will burn less fuel without providing electric than with electric and air?
I believe the APU should be stabilized for 1 min before using bleed. No limitation on using either one independently other than the altitude limits. So, yes you can use the APU bleed without the APU GEN. The only problem I can see is the possibility of the ground crew disconnecting GPU without notifying you if they hear the APU.