#1. An interesting procedure. Not heard of that one. I have my own method of leak determination before balancing. And I never flew with an airline that had an SOP for such. They rather naively, in today's market, relied on airmanship. And loom where that got the A330.
To answer the direct question; is there not a fuel totaliser computer gizmo thingie?
#2. The bleed switches, or one bleed switch, should be in the planned take off position to give the correct % expected to be seen on the N1% gauge and cross checked with the FMC Takeoff indication.
If I remember correctly the FMC receives the Bleeds On/Off information from the Bleed switch. At this stage of flight preparation one would expect to have the APU running for cabin air con'. Thus the manifold is pressurised, but I still think it is from the Bleed switch with pressure or not.