It appears that each time the Splitter is used, it takes time to recharge, so it must have massive capacitors to store the charge.
Interestingly JACK seems sanguine about the fact that if the past is changed he might cease to exist.
I was wondering why TORRES didn't just eliminate JUNIOR HENDERSON in the original transport, this explains it.
TORRES also realises that her's is a suicide mission.
TORRES is super-smart and seems to have done everything she can to get a successful outcome to the mission, including the fact that JACK could be convinced to switch loyalties.