I'm pulling a brain fart right now...
If someone with multiple arrows to attack uses a shield for a ranged shot, does the shield up BOTH the shots, or just the first?

Both.

And the reason is that it isn't divided into a first and second shot. There is only one attack being made---it targets multiple figures, but all of the attack occurs simultaneously.

If you have multiple lightning bolts, don't you have to roll multiple times to attack each character to set off the energy explosion?

Nope, you make a single attack roll and compare it against each target's defense. This applies to multi-target attacks as well as EE.