OK, sorry if these have been answered. I've done my best to search and scour on this topic and I'm still not 100% clear.
1) The general gist is: the more damage a vessel takes, the less effective firepower becomes on the vessel, right?
2) Are damage & shield mitigation the same things, just one applies to reducing damage to hull and one applies to reducing it to shields?
3) So I understand for this reason that I generally don't want to focus fire on a single target with a big fleet. So, one option is to let the AI pick targets. However, in some situations, I absolutely want to destroy a particular enemy vessel first -- for example, an Advent Battlecruiser that keeps casting shield restore. How can I tell what the right amount of vessels are to have firing on it, without wasting firepower?